Merge pull request #3223 from ethomson/apply

Reading patch files

include/git2/diff.h

@@ -264,10 +264,15 @@ typedef enum {
  * link, a submodule commit id, or even a tree (although that only if you
  * are tracking type changes or ignored/untracked directories).
  *
- * The `oid` is the `git_oid` of the item.  If the entry represents an
+ * The `id` is the `git_oid` of the item.  If the entry represents an
  * absent side of a diff (e.g. the `old_file` of a `GIT_DELTA_ADDED` delta),
  * then the oid will be zeroes.
  *
+ * The `id_abbrev` represents the known length of the `id` field, when
+ * converted to a hex string.  It is generally `GIT_OID_HEXSZ`, unless this
+ * delta was created from reading a patch file, in which case it may be
+ * abbreviated to something reasonable, like 7 characters.
+ *
  * `path` is the NUL-terminated path to the entry relative to the working
  * directory of the repository.
  *
@@ -280,6 +285,7 @@ typedef enum {
  */
 typedef struct {
 	git_oid     id;
+	int         id_abbrev;
 	const char *path;
 	git_off_t   size;
 	uint32_t    flags;
@@ -448,6 +454,8 @@ typedef int (*git_diff_file_cb)(
 	float progress,
 	void *payload);
 
+#define GIT_DIFF_HUNK_HEADER_SIZE	128
+
 /**
  * When producing a binary diff, the binary data returned will be
  * either the deflated full ("literal") contents of the file, or
@@ -499,12 +507,12 @@ typedef int(*git_diff_binary_cb)(
  * Structure describing a hunk of a diff.
  */
 typedef struct {
-	int    old_start;     /**< Starting line number in old_file */
-	int    old_lines;     /**< Number of lines in old_file */
-	int    new_start;     /**< Starting line number in new_file */
-	int    new_lines;     /**< Number of lines in new_file */
-	size_t header_len;    /**< Number of bytes in header text */
-	char   header[128];   /**< Header text, NUL-byte terminated */
+	int    old_start;     /** Starting line number in old_file */
+	int    old_lines;     /** Number of lines in old_file */
+	int    new_start;     /** Starting line number in new_file */
+	int    new_lines;     /** Number of lines in new_file */
+	size_t header_len;    /** Number of bytes in header text */
+	char   header[GIT_DIFF_HUNK_HEADER_SIZE];   /** Header text, NUL-byte terminated */
 } git_diff_hunk;
 
 /**
@@ -1046,6 +1054,21 @@ GIT_EXTERN(int) git_diff_print(
 	git_diff_line_cb print_cb,
 	void *payload);
 
+/**
+ * Produce the complete formatted text output from a diff into a
+ * buffer.
+ *
+ * @param out A pointer to a user-allocated git_buf that will
+ *            contain the diff text
+ * @param diff A git_diff generated by one of the above functions.
+ * @param format A git_diff_format_t value to pick the text format.
+ * @return 0 on success or error code
+ */
+GIT_EXTERN(int) git_diff_to_buf(
+	git_buf *out,
+	git_diff *diff,
+	git_diff_format_t format);
+
 /**@}*/
 
 
@@ -1166,6 +1189,11 @@ GIT_EXTERN(int) git_diff_buffers(
 	git_diff_line_cb line_cb,
 	void *payload);
 
+GIT_EXTERN(int) git_diff_from_buffer(
+	git_diff **out,
+	const char *content,
+	size_t content_len);
+
 /**
  * This is an opaque structure which is allocated by `git_diff_get_stats`.
  * You are responsible for releasing the object memory when done, using the

include/git2/errors.h

@@ -98,7 +98,8 @@ typedef enum {
 	GITERR_CHERRYPICK,
 	GITERR_DESCRIBE,
 	GITERR_REBASE,
-	GITERR_FILESYSTEM
+	GITERR_FILESYSTEM,
+	GITERR_PATCH,
 } git_error_t;
 
 /**

src/apply.c

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include <assert.h>
+
+#include "git2/patch.h"
+#include "git2/filter.h"
+#include "array.h"
+#include "patch.h"
+#include "fileops.h"
+#include "apply.h"
+#include "delta.h"
+#include "zstream.h"
+
+#define apply_err(...) \
+	( giterr_set(GITERR_PATCH, __VA_ARGS__), -1 )
+
+typedef struct {
+	/* The lines that we allocate ourself are allocated out of the pool.
+	 * (Lines may have been allocated out of the diff.)
+	 */
+	git_pool pool;
+	git_vector lines;
+} patch_image;
+
+static void patch_line_init(
+	git_diff_line *out,
+	const char *in,
+	size_t in_len,
+	size_t in_offset)
+{
+	out->content = in;
+	out->content_len = in_len;
+	out->content_offset = in_offset;
+}
+
+#define PATCH_IMAGE_INIT { {0} }
+
+static int patch_image_init_fromstr(
+	patch_image *out, const char *in, size_t in_len)
+{
+	git_diff_line *line;
+	const char *start, *end;
+
+	memset(out, 0x0, sizeof(patch_image));
+
+	git_pool_init(&out->pool, sizeof(git_diff_line));
+
+	for (start = in; start < in + in_len; start = end) {
+		end = memchr(start, '\n', in_len);
+
+		if (end < in + in_len)
+			end++;
+
+		line = git_pool_mallocz(&out->pool, 1);
+		GITERR_CHECK_ALLOC(line);
+
+		if (git_vector_insert(&out->lines, line) < 0)
+			return -1;
+
+		patch_line_init(line, start, (end - start), (start - in));
+	}
+
+	return 0;
+}
+
+static void patch_image_free(patch_image *image)
+{
+	if (image == NULL)
+		return;
+
+	git_pool_clear(&image->pool);
+	git_vector_free(&image->lines);
+}
+
+static bool match_hunk(
+	patch_image *image,
+	patch_image *preimage,
+	size_t linenum)
+{
+	bool match = 0;
+	size_t i;
+
+	/* Ensure this hunk is within the image boundaries. */
+	if (git_vector_length(&preimage->lines) + linenum >
+		git_vector_length(&image->lines))
+		return 0;
+
+	match = 1;
+
+	/* Check exact match. */
+	for (i = 0; i < git_vector_length(&preimage->lines); i++) {
+		git_diff_line *preimage_line = git_vector_get(&preimage->lines, i);
+		git_diff_line *image_line = git_vector_get(&image->lines, linenum + i);
+
+		if (preimage_line->content_len != preimage_line->content_len ||
+			memcmp(preimage_line->content, image_line->content, image_line->content_len) != 0) {
+			match = 0;
+			break;
+		}
+	}
+
+	return match;
+}
+
+static bool find_hunk_linenum(
+	size_t *out,
+	patch_image *image,
+	patch_image *preimage,
+	size_t linenum)
+{
+	size_t max = git_vector_length(&image->lines);
+	bool match;
+
+	if (linenum > max)
+		linenum = max;
+
+	match = match_hunk(image, preimage, linenum);
+
+	*out = linenum;
+	return match;
+}
+
+static int update_hunk(
+	patch_image *image,
+	unsigned int linenum,
+	patch_image *preimage,
+	patch_image *postimage)
+{
+	size_t postlen = git_vector_length(&postimage->lines);
+	size_t prelen = git_vector_length(&preimage->lines);
+	size_t i;
+	int error = 0;
+
+	if (postlen > prelen)
+		error = git_vector_insert_null(
+			&image->lines, linenum, (postlen - prelen));
+	else if (prelen > postlen)
+		error = git_vector_remove_range(
+			&image->lines, linenum, (prelen - postlen));
+
+	if (error) {
+		giterr_set_oom();
+		return -1;
+	}
+
+	for (i = 0; i < git_vector_length(&postimage->lines); i++) {
+		image->lines.contents[linenum + i] =
+			git_vector_get(&postimage->lines, i);
+	}
+
+	return 0;
+}
+
+static int apply_hunk(
+	patch_image *image,
+	git_patch *patch,
+	git_patch_hunk *hunk)
+{
+	patch_image preimage = PATCH_IMAGE_INIT, postimage = PATCH_IMAGE_INIT;
+	size_t line_num, i;
+	int error = 0;
+
+	for (i = 0; i < hunk->line_count; i++) {
+		size_t linenum = hunk->line_start + i;
+		git_diff_line *line = git_array_get(patch->lines, linenum);
+
+		if (!line) {
+			error = apply_err("Preimage does not contain line %d", linenum);
+			goto done;
+		}
+
+		if (line->origin == GIT_DIFF_LINE_CONTEXT ||
+			line->origin == GIT_DIFF_LINE_DELETION) {
+			if ((error = git_vector_insert(&preimage.lines, line)) < 0)
+				goto done;
+		}
+
+		if (line->origin == GIT_DIFF_LINE_CONTEXT ||
+			line->origin == GIT_DIFF_LINE_ADDITION) {
+			if ((error = git_vector_insert(&postimage.lines, line)) < 0)
+				goto done;
+		}
+	}
+
+	line_num = hunk->hunk.new_start ? hunk->hunk.new_start - 1 : 0;
+
+	if (!find_hunk_linenum(&line_num, image, &preimage, line_num)) {
+		error = apply_err("Hunk at line %d did not apply",
+			hunk->hunk.new_start);
+		goto done;
+	}
+
+	error = update_hunk(image, line_num, &preimage, &postimage);
+
+done:
+	patch_image_free(&preimage);
+	patch_image_free(&postimage);
+
+	return error;
+}
+
+static int apply_hunks(
+	git_buf *out,
+	const char *source,
+	size_t source_len,
+	git_patch *patch)
+{
+	git_patch_hunk *hunk;
+	git_diff_line *line;
+	patch_image image;
+	size_t i;
+	int error = 0;
+
+	if ((error = patch_image_init_fromstr(&image, source, source_len)) < 0)
+		goto done;
+
+	git_array_foreach(patch->hunks, i, hunk) {
+		if ((error = apply_hunk(&image, patch, hunk)) < 0)
+			goto done;
+	}
+
+	git_vector_foreach(&image.lines, i, line)
+		git_buf_put(out, line->content, line->content_len);
+
+done:
+	patch_image_free(&image);
+
+	return error;
+}
+
+static int apply_binary_delta(
+	git_buf *out,
+	const char *source,
+	size_t source_len,
+	git_diff_binary_file *binary_file)
+{
+	git_buf inflated = GIT_BUF_INIT;
+	int error = 0;
+
+	/* no diff means identical contents */
+	if (binary_file->datalen == 0)
+		return git_buf_put(out, source, source_len);
+
+	error = git_zstream_inflatebuf(&inflated,
+		binary_file->data, binary_file->datalen);
+
+	if (!error && inflated.size != binary_file->inflatedlen) {
+		error = apply_err("inflated delta does not match expected length");
+		git_buf_free(out);
+	}
+
+	if (error < 0)
+		goto done;
+
+	if (binary_file->type == GIT_DIFF_BINARY_DELTA) {
+		void *data;
+		size_t data_len;
+
+		error = git_delta_apply(&data, &data_len, (void *)source, source_len,
+			(void *)inflated.ptr, inflated.size);
+
+		out->ptr = data;
+		out->size = data_len;
+		out->asize = data_len;
+	}
+	else if (binary_file->type == GIT_DIFF_BINARY_LITERAL) {
+		git_buf_swap(out, &inflated);
+	}
+	else {
+		error = apply_err("unknown binary delta type");
+		goto done;
+	}
+
+done:
+	git_buf_free(&inflated);
+	return error;
+}
+
+static int apply_binary(
+	git_buf *out,
+	const char *source,
+	size_t source_len,
+	git_patch *patch)
+{
+	git_buf reverse = GIT_BUF_INIT;
+	int error;
+
+	/* first, apply the new_file delta to the given source */
+	if ((error = apply_binary_delta(out, source, source_len,
+			&patch->binary.new_file)) < 0)
+		goto done;
+
+	/* second, apply the old_file delta to sanity check the result */
+	if ((error = apply_binary_delta(&reverse, out->ptr, out->size,
+			&patch->binary.old_file)) < 0)
+		goto done;
+
+	if (source_len != reverse.size ||
+		memcmp(source, reverse.ptr, source_len) != 0) {
+		error = apply_err("binary patch did not apply cleanly");
+		goto done;
+	}
+
+done:
+	if (error < 0)
+		git_buf_free(out);
+
+	git_buf_free(&reverse);
+	return error;
+}
+
+int git_apply__patch(
+	git_buf *contents_out,
+	char **filename_out,
+	unsigned int *mode_out,
+	const char *source,
+	size_t source_len,
+	git_patch *patch)
+{
+	char *filename = NULL;
+	unsigned int mode = 0;
+	int error = 0;
+
+	assert(contents_out && filename_out && mode_out && (source || !source_len) && patch);
+
+	*filename_out = NULL;
+	*mode_out = 0;
+
+	if (patch->delta->status != GIT_DELTA_DELETED) {
+		const git_diff_file *newfile = &patch->delta->new_file;
+
+		filename = git__strdup(newfile->path);
+		mode = newfile->mode ?
+			newfile->mode : GIT_FILEMODE_BLOB;
+	}
+
+	if (patch->delta->flags & GIT_DIFF_FLAG_BINARY)
+		error = apply_binary(contents_out, source, source_len, patch);
+	else if (patch->hunks.size)
+		error = apply_hunks(contents_out, source, source_len, patch);
+	else
+		error = git_buf_put(contents_out, source, source_len);
+
+	if (error)
+		goto done;
+
+	if (patch->delta->status == GIT_DELTA_DELETED &&
+		git_buf_len(contents_out) > 0) {
+		error = apply_err("removal patch leaves file contents");
+		goto done;
+	}
+
+	*filename_out = filename;
+	*mode_out = mode;
+
+done:
+	if (error < 0)
+		git__free(filename);
+
+	return error;
+}

src/apply.h

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_apply_h__
+#define INCLUDE_apply_h__
+
+#include "git2/patch.h"
+#include "buffer.h"
+
+extern int git_apply__patch(
+	git_buf *out,
+	char **filename,
+	unsigned int *mode,
+	const char *source,
+	size_t source_len,
+	git_patch *patch);
+
+#endif

src/array.h

@@ -85,7 +85,6 @@ on_oom:
 #define git_array_foreach(a, i, element) \
 	for ((i) = 0; (i) < (a).size && ((element) = &(a).ptr[(i)]); (i)++)
 
-
 GIT_INLINE(int) git_array__search(
 	size_t *out,
 	void *array_ptr,

src/buffer.c

@@ -273,42 +273,51 @@ int git_buf_encode_base64(git_buf *buf, const char *data, size_t len)
 	return 0;
 }
 
-/* The inverse of base64_encode, offset by '+' == 43. */
+/* The inverse of base64_encode */
 static const int8_t base64_decode[] = {
-	62,
-	-1, -1, -1,
-	63,
-	52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
-	-1, -1, -1, 0, -1, -1, -1,
-	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
-	13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
-	-1, -1, -1, -1, -1, -1,
-	26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
-	39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1,  0, -1, -1,
+	-1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+	-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
 };
 
-#define BASE64_DECODE_VALUE(c) (((c) < 43 || (c) > 122) ? -1 : base64_decode[c - 43])
-
 int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len)
 {
 	size_t i;
 	int8_t a, b, c, d;
 	size_t orig_size = buf->size, new_size;
 
+	if (len % 4) {
+		giterr_set(GITERR_INVALID, "invalid base64 input");
+		return -1;
+	}
+
 	assert(len % 4 == 0);
 	GITERR_CHECK_ALLOC_ADD(&new_size, (len / 4 * 3), buf->size);
 	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
 	ENSURE_SIZE(buf, new_size);
 
 	for (i = 0; i < len; i += 4) {
-		if ((a = BASE64_DECODE_VALUE(base64[i])) < 0 ||
-			(b = BASE64_DECODE_VALUE(base64[i+1])) < 0 ||
-			(c = BASE64_DECODE_VALUE(base64[i+2])) < 0 ||
-			(d = BASE64_DECODE_VALUE(base64[i+3])) < 0) {
+		if ((a = base64_decode[(unsigned char)base64[i]]) < 0 ||
+			(b = base64_decode[(unsigned char)base64[i+1]]) < 0 ||
+			(c = base64_decode[(unsigned char)base64[i+2]]) < 0 ||
+			(d = base64_decode[(unsigned char)base64[i+3]]) < 0) {
 			buf->size = orig_size;
 			buf->ptr[buf->size] = '\0';
 
-			giterr_set(GITERR_INVALID, "Invalid base64 input");
+			giterr_set(GITERR_INVALID, "invalid base64 input");
 			return -1;
 		}
 
@@ -321,7 +330,7 @@ int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len)
 	return 0;
 }
 
-static const char b85str[] =
+static const char base85_encode[] =
 	"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
 
 int git_buf_encode_base85(git_buf *buf, const char *data, size_t len)
@@ -351,7 +360,7 @@ int git_buf_encode_base85(git_buf *buf, const char *data, size_t len)
 			int val = acc % 85;
 			acc /= 85;
 
-			b85[i] = b85str[val];
+			b85[i] = base85_encode[val];
 		}
 
 		for (i = 0; i < 5; i++)
@@ -363,6 +372,88 @@ int git_buf_encode_base85(git_buf *buf, const char *data, size_t len)
 	return 0;
 }
 
+/* The inverse of base85_encode */
+static const int8_t base85_decode[] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, 63, -1, 64, 65, 66, 67, -1, 68, 69, 70, 71, -1, 72, -1, -1,
+	 1,  2,  3,  4,  5,  6,  7,  8,  9, 10, -1, 73, 74, 75, 76, 77,
+	78, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
+	26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, -1, -1, -1, 79, 80,
+	81, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
+	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 82, 83, 84, 85, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+};
+
+int git_buf_decode_base85(
+	git_buf *buf,
+	const char *base85,
+	size_t base85_len,
+	size_t output_len)
+{
+	size_t orig_size = buf->size, new_size;
+
+	if (base85_len % 5 ||
+		output_len > base85_len * 4 / 5) {
+		giterr_set(GITERR_INVALID, "invalid base85 input");
+		return -1;
+	}
+
+	GITERR_CHECK_ALLOC_ADD(&new_size, output_len, buf->size);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+	ENSURE_SIZE(buf, new_size);
+
+	while (output_len) {
+		unsigned acc = 0;
+		int de, cnt = 4;
+		unsigned char ch;
+		do {
+			ch = *base85++;
+			de = base85_decode[ch];
+			if (--de < 0)
+				goto on_error;
+
+			acc = acc * 85 + de;
+		} while (--cnt);
+		ch = *base85++;
+		de = base85_decode[ch];
+		if (--de < 0)
+			goto on_error;
+
+		/* Detect overflow. */
+		if (0xffffffff / 85 < acc ||
+			0xffffffff - de < (acc *= 85))
+			goto on_error;
+
+		acc += de;
+
+		cnt = (output_len < 4) ? output_len : 4;
+		output_len -= cnt;
+		do {
+			acc = (acc << 8) | (acc >> 24);
+			buf->ptr[buf->size++] = acc;
+		} while (--cnt);
+	}
+
+	buf->ptr[buf->size] = 0;
+
+	return 0;
+
+on_error:
+	buf->size = orig_size;
+	buf->ptr[buf->size] = '\0';
+
+	giterr_set(GITERR_INVALID, "invalid base85 input");
+	return -1;
+}
+
 int git_buf_vprintf(git_buf *buf, const char *format, va_list ap)
 {
 	size_t expected_size, new_size;
@@ -766,3 +857,144 @@ int git_buf_splice(
 	buf->ptr[buf->size] = '\0';
 	return 0;
 }
+
+/* Quote per http://marc.info/?l=git&m=112927316408690&w=2 */
+int git_buf_quote(git_buf *buf)
+{
+	const char whitespace[] = { 'a', 'b', 't', 'n', 'v', 'f', 'r' };
+	git_buf quoted = GIT_BUF_INIT;
+	size_t i = 0;
+	bool quote = false;
+	int error = 0;
+
+	/* walk to the first char that needs quoting */
+	if (buf->size && buf->ptr[0] == '!')
+		quote = true;
+
+	for (i = 0; !quote && i < buf->size; i++) {
+		if (buf->ptr[i] == '"' || buf->ptr[i] == '\\' ||
+			buf->ptr[i] < ' ' || buf->ptr[i] > '~') {
+			quote = true;
+			break;
+		}
+	}
+
+	if (!quote)
+		goto done;
+
+	git_buf_putc(&quoted, '"');
+	git_buf_put(&quoted, buf->ptr, i);
+
+	for (; i < buf->size; i++) {
+		/* whitespace - use the map above, which is ordered by ascii value */
+		if (buf->ptr[i] >= '\a' && buf->ptr[i] <= '\r') {
+			git_buf_putc(&quoted, '\\');
+			git_buf_putc(&quoted, whitespace[buf->ptr[i] - '\a']);
+		}
+
+		/* double quote and backslash must be escaped */
+		else if (buf->ptr[i] == '"' || buf->ptr[i] == '\\') {
+			git_buf_putc(&quoted, '\\');
+			git_buf_putc(&quoted, buf->ptr[i]);
+		}
+
+		/* escape anything unprintable as octal */
+		else if (buf->ptr[i] != ' ' &&
+				(buf->ptr[i] < '!' || buf->ptr[i] > '~')) {
+			git_buf_printf(&quoted, "\\%03o", (unsigned char)buf->ptr[i]);
+		}
+
+		/* yay, printable! */
+		else {
+			git_buf_putc(&quoted, buf->ptr[i]);
+		}
+	}
+
+	git_buf_putc(&quoted, '"');
+
+	if (git_buf_oom(&quoted)) {
+		error = -1;
+		goto done;
+	}
+
+	git_buf_swap(&quoted, buf);
+
+done:
+	git_buf_free(&quoted);
+	return error;
+}
+
+/* Unquote per http://marc.info/?l=git&m=112927316408690&w=2 */
+int git_buf_unquote(git_buf *buf)
+{
+	size_t i, j;
+	char ch;
+
+	git_buf_rtrim(buf);
+
+	if (buf->size < 2 || buf->ptr[0] != '"' || buf->ptr[buf->size-1] != '"')
+		goto invalid;
+
+	for (i = 0, j = 1; j < buf->size-1; i++, j++) {
+		ch = buf->ptr[j];
+
+		if (ch == '\\') {
+			if (j == buf->size-2)
+				goto invalid;
+
+			ch = buf->ptr[++j];
+
+			switch (ch) {
+			/* \" or \\ simply copy the char in */
+			case '"': case '\\':
+				break;
+
+			/* add the appropriate escaped char */
+			case 'a': ch = '\a'; break;
+			case 'b': ch = '\b'; break;
+			case 'f': ch = '\f'; break;
+			case 'n': ch = '\n'; break;
+			case 'r': ch = '\r'; break;
+			case 't': ch = '\t'; break;
+			case 'v': ch = '\v'; break;
+
+			/* \xyz digits convert to the char*/
+			case '0': case '1': case '2': case '3':
+				if (j == buf->size-3) {
+					giterr_set(GITERR_INVALID,
+						"Truncated quoted character \\%c", ch);
+					return -1;
+				}
+
+				if (buf->ptr[j+1] < '0' || buf->ptr[j+1] > '7' ||
+					buf->ptr[j+2] < '0' || buf->ptr[j+2] > '7') {
+					giterr_set(GITERR_INVALID,
+						"Truncated quoted character \\%c%c%c",
+						buf->ptr[j], buf->ptr[j+1], buf->ptr[j+2]);
+					return -1;
+				}
+
+				ch = ((buf->ptr[j] - '0') << 6) |
+					((buf->ptr[j+1] - '0') << 3) |
+					(buf->ptr[j+2] - '0');
+				j += 2;
+				break;
+
+			default:
+				giterr_set(GITERR_INVALID, "Invalid quoted character \\%c", ch);
+				return -1;
+			}
+		}
+
+		buf->ptr[i] = ch;
+	}
+
+	buf->ptr[i] = '\0';
+	buf->size = i;
+
+	return 0;
+
+invalid:
+	giterr_set(GITERR_INVALID, "Invalid quoted line");
+	return -1;
+}

src/buffer.h

@@ -173,6 +173,12 @@ void git_buf_rtrim(git_buf *buf);
 
 int git_buf_cmp(const git_buf *a, const git_buf *b);
 
+/* Quote and unquote a buffer as specified in
+ * http://marc.info/?l=git&m=112927316408690&w=2
+ */
+int git_buf_quote(git_buf *buf);
+int git_buf_unquote(git_buf *buf);
+
 /* Write data as base64 encoded in buffer */
 int git_buf_encode_base64(git_buf *buf, const char *data, size_t len);
 /* Decode the given bas64 and write the result to the buffer */
@@ -180,6 +186,8 @@ int git_buf_decode_base64(git_buf *buf, const char *base64, size_t len);
 
 /* Write data as "base85" encoded in buffer */
 int git_buf_encode_base85(git_buf *buf, const char *data, size_t len);
+/* Decode the given "base85" and write the result to the buffer */
+int git_buf_decode_base85(git_buf *buf, const char *base64, size_t len, size_t output_len);
 
 /*
  * Insert, remove or replace a portion of the buffer.

src/checkout.c

@@ -26,6 +26,7 @@
 #include "filter.h"
 #include "blob.h"
 #include "diff.h"
+#include "diff_generate.h"
 #include "pathspec.h"
 #include "buf_text.h"
 #include "diff_xdiff.h"

src/delta-apply.c

-/*
- * Copyright (C) the libgit2 contributors. All rights reserved.
- *
- * This file is part of libgit2, distributed under the GNU GPL v2 with
- * a Linking Exception. For full terms see the included COPYING file.
- */
-#include "common.h"
-#include "git2/odb.h"
-#include "delta-apply.h"
-
-/*
- * This file was heavily cribbed from BinaryDelta.java in JGit, which
- * itself was heavily cribbed from <code>patch-delta.c</code> in the
- * GIT project.	The original delta patching code was written by
- * Nicolas Pitre <nico@cam.org>.
- */
-
-static int hdr_sz(
-	size_t *size,
-	const unsigned char **delta,
-	const unsigned char *end)
-{
-	const unsigned char *d = *delta;
-	size_t r = 0;
-	unsigned int c, shift = 0;
-
-	do {
-		if (d == end)
-			return -1;
-		c = *d++;
-		r |= (c & 0x7f) << shift;
-		shift += 7;
-	} while (c & 0x80);
-	*delta = d;
-	*size = r;
-	return 0;
-}
-
-int git__delta_read_header(
-	const unsigned char *delta,
-	size_t delta_len,
-	size_t *base_sz,
-	size_t *res_sz)
-{
-	const unsigned char *delta_end = delta + delta_len;
-	if ((hdr_sz(base_sz, &delta, delta_end) < 0) ||
-	    (hdr_sz(res_sz, &delta, delta_end) < 0))
-		return -1;
-	return 0;
-}
-
-#define DELTA_HEADER_BUFFER_LEN 16
-int git__delta_read_header_fromstream(size_t *base_sz, size_t *res_sz, git_packfile_stream *stream)
-{
-	static const size_t buffer_len = DELTA_HEADER_BUFFER_LEN;
-	unsigned char buffer[DELTA_HEADER_BUFFER_LEN];
-	const unsigned char *delta, *delta_end;
-	size_t len;
-	ssize_t read;
-
-	len = read = 0;
-	while (len < buffer_len) {
-		read = git_packfile_stream_read(stream, &buffer[len], buffer_len - len);
-
-		if (read == 0)
-			break;
-
-		if (read == GIT_EBUFS)
-			continue;
-
-		len += read;
-	}
-
-	delta = buffer;
-	delta_end = delta + len;
-	if ((hdr_sz(base_sz, &delta, delta_end) < 0) ||
-	    (hdr_sz(res_sz, &delta, delta_end) < 0))
-		return -1;
-
-	return 0;
-}
-
-int git__delta_apply(
-	git_rawobj *out,
-	const unsigned char *base,
-	size_t base_len,
-	const unsigned char *delta,
-	size_t delta_len)
-{
-	const unsigned char *delta_end = delta + delta_len;
-	size_t base_sz, res_sz, alloc_sz;
-	unsigned char *res_dp;
-
-	/* Check that the base size matches the data we were given;
-	 * if not we would underflow while accessing data from the
-	 * base object, resulting in data corruption or segfault.
-	 */
-	if ((hdr_sz(&base_sz, &delta, delta_end) < 0) || (base_sz != base_len)) {
-		giterr_set(GITERR_INVALID, "Failed to apply delta. Base size does not match given data");
-		return -1;
-	}
-
-	if (hdr_sz(&res_sz, &delta, delta_end) < 0) {
-		giterr_set(GITERR_INVALID, "Failed to apply delta. Base size does not match given data");
-		return -1;
-	}
-
-	GITERR_CHECK_ALLOC_ADD(&alloc_sz, res_sz, 1);
-	res_dp = git__malloc(alloc_sz);
-	GITERR_CHECK_ALLOC(res_dp);
-
-	res_dp[res_sz] = '\0';
-	out->data = res_dp;
-	out->len = res_sz;
-
-	while (delta < delta_end) {
-		unsigned char cmd = *delta++;
-		if (cmd & 0x80) {
-			/* cmd is a copy instruction; copy from the base.
-			 */
-			size_t off = 0, len = 0;
-
-			if (cmd & 0x01) off = *delta++;
-			if (cmd & 0x02) off |= *delta++ << 8UL;
-			if (cmd & 0x04) off |= *delta++ << 16UL;
-			if (cmd & 0x08) off |= *delta++ << 24UL;
-
-			if (cmd & 0x10) len = *delta++;
-			if (cmd & 0x20) len |= *delta++ << 8UL;
-			if (cmd & 0x40) len |= *delta++ << 16UL;
-			if (!len)		len = 0x10000;
-
-			if (base_len < off + len || res_sz < len)
-				goto fail;
-			memcpy(res_dp, base + off, len);
-			res_dp += len;
-			res_sz -= len;
-
-		} else if (cmd) {
-			/* cmd is a literal insert instruction; copy from
-			 * the delta stream itself.
-			 */
-			if (delta_end - delta < cmd || res_sz < cmd)
-				goto fail;
-			memcpy(res_dp, delta, cmd);
-			delta += cmd;
-			res_dp += cmd;
-			res_sz -= cmd;
-
-		} else {
-			/* cmd == 0 is reserved for future encodings.
-			 */
-			goto fail;
-		}
-	}
-
-	if (delta != delta_end || res_sz)
-		goto fail;
-	return 0;
-
-fail:
-	git__free(out->data);
-	out->data = NULL;
-	giterr_set(GITERR_INVALID, "Failed to apply delta");
-	return -1;
-}

src/delta-apply.h

-/*
- * Copyright (C) the libgit2 contributors. All rights reserved.
- *
- * This file is part of libgit2, distributed under the GNU GPL v2 with
- * a Linking Exception. For full terms see the included COPYING file.
- */
-#ifndef INCLUDE_delta_apply_h__
-#define INCLUDE_delta_apply_h__
-
-#include "odb.h"
-#include "pack.h"
-
-/**
- * Apply a git binary delta to recover the original content.
- *
- * @param out the output buffer to receive the original data.
- *		Only out->data and out->len are populated, as this is
- *		the only information available in the delta.
- * @param base the base to copy from during copy instructions.
- * @param base_len number of bytes available at base.
- * @param delta the delta to execute copy/insert instructions from.
- * @param delta_len total number of bytes in the delta.
- * @return
- * - 0 on a successful delta unpack.
- * - GIT_ERROR if the delta is corrupt or doesn't match the base.
- */
-extern int git__delta_apply(
-	git_rawobj *out,
-	const unsigned char *base,
-	size_t base_len,
-	const unsigned char *delta,
-	size_t delta_len);
-
-/**
- * Read the header of a git binary delta.
- *
- * @param delta the delta to execute copy/insert instructions from.
- * @param delta_len total number of bytes in the delta.
- * @param base_sz pointer to store the base size field.
- * @param res_sz pointer to store the result size field.
- * @return
- * - 0 on a successful decoding the header.
- * - GIT_ERROR if the delta is corrupt.
- */
-extern int git__delta_read_header(
-	const unsigned char *delta,
-	size_t delta_len,
-	size_t *base_sz,
-	size_t *res_sz);
-
-/**
- * Read the header of a git binary delta
- *
- * This variant reads just enough from the packfile stream to read the
- * delta header.
- */
-extern int git__delta_read_header_fromstream(
-	size_t *base_sz,
-	size_t *res_sz,
-	git_packfile_stream *stream);
-
-#endif

src/delta.h

@@ -6,12 +6,12 @@
 #define INCLUDE_git_delta_h__
 
 #include "common.h"
+#include "pack.h"
 
-/* opaque object for delta index */
-struct git_delta_index;
+typedef struct git_delta_index git_delta_index;
 
 /*
- * create_delta_index: compute index data from given buffer
+ * git_delta_index_init: compute index data from given buffer
  *
  * This returns a pointer to a struct delta_index that should be passed to
  * subsequent create_delta() calls, or to free_delta_index().  A NULL pointer
@@ -19,22 +19,18 @@ struct git_delta_index;
  * before free_delta_index() is called.  The returned pointer must be freed
  * using free_delta_index().
  */
-extern struct git_delta_index *
-git_delta_create_index(const void *buf, unsigned long bufsize);
+extern int git_delta_index_init(
+	git_delta_index **out, const void *buf, size_t bufsize);
 
 /*
- * free_delta_index: free the index created by create_delta_index()
- *
- * Given pointer must be what create_delta_index() returned, or NULL.
+ * Free the index created by git_delta_index_init()
  */
-extern void git_delta_free_index(struct git_delta_index *index);
+extern void git_delta_index_free(git_delta_index *index);
 
 /*
- * sizeof_delta_index: returns memory usage of delta index
- *
- * Given pointer must be what create_delta_index() returned, or NULL.
+ * Returns memory usage of delta index.
  */
-extern unsigned long git_delta_sizeof_index(struct git_delta_index *index);
+extern size_t git_delta_index_size(git_delta_index *index);
 
 /*
  * create_delta: create a delta from given index for the given buffer
@@ -46,69 +42,94 @@ extern unsigned long git_delta_sizeof_index(struct git_delta_index *index);
  * returned and *delta_size is updated with its size.  The returned buffer
  * must be freed by the caller.
  */
-extern void *git_delta_create(
+extern int git_delta_create_from_index(
+	void **out,
+	size_t *out_size,
 	const struct git_delta_index *index,
 	const void *buf,
-	unsigned long bufsize,
-	unsigned long *delta_size,
-	unsigned long max_delta_size);
+	size_t bufsize,
+	size_t max_delta_size);
 
 /*
  * diff_delta: create a delta from source buffer to target buffer
  *
  * If max_delta_size is non-zero and the resulting delta is to be larger
- * than max_delta_size then NULL is returned.  On success, a non-NULL
+ * than max_delta_size then GIT_EBUFS is returned.  On success, a non-NULL
  * pointer to the buffer with the delta data is returned and *delta_size is
  * updated with its size.  The returned buffer must be freed by the caller.
  */
-GIT_INLINE(void *) git_delta(
-	const void *src_buf, unsigned long src_bufsize,
-	const void *trg_buf, unsigned long trg_bufsize,
-	unsigned long *delta_size,
-	unsigned long max_delta_size)
+GIT_INLINE(int) git_delta(
+	void **out, size_t *out_len,
+	const void *src_buf, size_t src_bufsize,
+	const void *trg_buf, size_t trg_bufsize,
+	size_t max_delta_size)
 {
-	struct git_delta_index *index = git_delta_create_index(src_buf, src_bufsize);
+	git_delta_index *index;
+	int error = 0;
+
+	*out = NULL;
+	*out_len = 0;
+
+	if ((error = git_delta_index_init(&index, src_buf, src_bufsize)) < 0)
+		return error;
+
 	if (index) {
-		void *delta = git_delta_create(
-			index, trg_buf, trg_bufsize, delta_size, max_delta_size);
-		git_delta_free_index(index);
-		return delta;
+		error = git_delta_create_from_index(out, out_len,
+			index, trg_buf, trg_bufsize, max_delta_size);
+
+		git_delta_index_free(index);
 	}
-	return NULL;
-}
 
-/*
- * patch_delta: recreate target buffer given source buffer and delta data
- *
- * On success, a non-NULL pointer to the target buffer is returned and
- * *trg_bufsize is updated with its size.  On failure a NULL pointer is
- * returned.  The returned buffer must be freed by the caller.
- */
-extern void *git_delta_patch(
-	const void *src_buf, unsigned long src_size,
-	const void *delta_buf, unsigned long delta_size,
-	unsigned long *dst_size);
+	return error;
+}
 
 /* the smallest possible delta size is 4 bytes */
 #define GIT_DELTA_SIZE_MIN	4
 
-/*
- * This must be called twice on the delta data buffer, first to get the
- * expected source buffer size, and again to get the target buffer size.
+/**
+* Apply a git binary delta to recover the original content.
+* The caller is responsible for freeing the returned buffer.
+*
+* @param out the output buffer
+* @param out_len the length of the output buffer
+* @param base the base to copy from during copy instructions.
+* @param base_len number of bytes available at base.
+* @param delta the delta to execute copy/insert instructions from.
+* @param delta_len total number of bytes in the delta.
+* @return 0 on success or an error code
+*/
+extern int git_delta_apply(
+	void **out,
+	size_t *out_len,
+	const unsigned char *base,
+	size_t base_len,
+	const unsigned char *delta,
+	size_t delta_len);
+
+/**
+* Read the header of a git binary delta.
+*
+* @param base_out pointer to store the base size field.
+* @param result_out pointer to store the result size field.
+* @param delta the delta to execute copy/insert instructions from.
+* @param delta_len total number of bytes in the delta.
+* @return 0 on success or an error code
+*/
+extern int git_delta_read_header(
+	size_t *base_out,
+	size_t *result_out,
+	const unsigned char *delta,
+	size_t delta_len);
+
+/**
+ * Read the header of a git binary delta
+ *
+ * This variant reads just enough from the packfile stream to read the
+ * delta header.
  */
-GIT_INLINE(unsigned long) git_delta_get_hdr_size(
-	const unsigned char **datap, const unsigned char *top)
-{
-	const unsigned char *data = *datap;
-	unsigned long cmd, size = 0;
-	int i = 0;
-	do {
-		cmd = *data++;
-		size |= (cmd & 0x7f) << i;
-		i += 7;
-	} while (cmd & 0x80 && data < top);
-	*datap = data;
-	return size;
-}
+extern int git_delta_read_header_fromstream(
+	size_t *base_out,
+	size_t *result_out,
+	git_packfile_stream *stream);
 
 #endif

src/diff.h

@@ -22,67 +22,30 @@
 #define DIFF_OLD_PREFIX_DEFAULT "a/"
 #define DIFF_NEW_PREFIX_DEFAULT "b/"
 
-enum {
-	GIT_DIFFCAPS_HAS_SYMLINKS     = (1 << 0), /* symlinks on platform? */
-	GIT_DIFFCAPS_IGNORE_STAT      = (1 << 1), /* use stat? */
-	GIT_DIFFCAPS_TRUST_MODE_BITS  = (1 << 2), /* use st_mode? */
-	GIT_DIFFCAPS_TRUST_CTIME      = (1 << 3), /* use st_ctime? */
-	GIT_DIFFCAPS_USE_DEV          = (1 << 4), /* use st_dev? */
-};
-
-#define DIFF_FLAGS_KNOWN_BINARY (GIT_DIFF_FLAG_BINARY|GIT_DIFF_FLAG_NOT_BINARY)
-#define DIFF_FLAGS_NOT_BINARY   (GIT_DIFF_FLAG_NOT_BINARY|GIT_DIFF_FLAG__NO_DATA)
-
-enum {
-	GIT_DIFF_FLAG__FREE_PATH  = (1 << 7),  /* `path` is allocated memory */
-	GIT_DIFF_FLAG__FREE_DATA  = (1 << 8),  /* internal file data is allocated */
-	GIT_DIFF_FLAG__UNMAP_DATA = (1 << 9),  /* internal file data is mmap'ed */
-	GIT_DIFF_FLAG__NO_DATA    = (1 << 10), /* file data should not be loaded */
-	GIT_DIFF_FLAG__FREE_BLOB  = (1 << 11), /* release the blob when done */
-	GIT_DIFF_FLAG__LOADED     = (1 << 12), /* file data has been loaded */
-
-	GIT_DIFF_FLAG__TO_DELETE  = (1 << 16), /* delete entry during rename det. */
-	GIT_DIFF_FLAG__TO_SPLIT   = (1 << 17), /* split entry during rename det. */
-	GIT_DIFF_FLAG__IS_RENAME_TARGET = (1 << 18),
-	GIT_DIFF_FLAG__IS_RENAME_SOURCE = (1 << 19),
-	GIT_DIFF_FLAG__HAS_SELF_SIMILARITY = (1 << 20),
-};
-
-#define GIT_DIFF_FLAG__CLEAR_INTERNAL(F) (F) = ((F) & 0x00FFFF)
-
-#define GIT_DIFF__VERBOSE  (1 << 30)
+typedef enum {
+	GIT_DIFF_TYPE_UNKNOWN = 0,
+	GIT_DIFF_TYPE_GENERATED = 1,
+	GIT_DIFF_TYPE_PARSED = 2,
+} git_diff_origin_t;
 
 struct git_diff {
 	git_refcount     rc;
 	git_repository   *repo;
+	git_diff_origin_t type;
 	git_diff_options opts;
-	git_vector       pathspec;
 	git_vector       deltas;    /* vector of git_diff_delta */
 	git_pool pool;
 	git_iterator_type_t old_src;
 	git_iterator_type_t new_src;
-	uint32_t diffcaps;
 	git_diff_perfdata perf;
-	bool index_updated;
 
 	int (*strcomp)(const char *, const char *);
 	int (*strncomp)(const char *, const char *, size_t);
 	int (*pfxcomp)(const char *str, const char *pfx);
 	int (*entrycomp)(const void *a, const void *b);
-};
-
-extern void git_diff__cleanup_modes(
-	uint32_t diffcaps, uint32_t *omode, uint32_t *nmode);
 
-extern void git_diff_addref(git_diff *diff);
-
-extern int git_diff_delta__cmp(const void *a, const void *b);
-extern int git_diff_delta__casecmp(const void *a, const void *b);
-
-extern const char *git_diff_delta__path(const git_diff_delta *delta);
-
-extern bool git_diff_delta__should_skip(
-	const git_diff_options *opts, const git_diff_delta *delta);
+	void (*free_fn)(git_diff *diff);
+};
 
 extern int git_diff_delta__format_file_header(
 	git_buf *out,
@@ -91,84 +54,11 @@ extern int git_diff_delta__format_file_header(
 	const char *newpfx,
 	int oid_strlen);
 
-extern int git_diff__oid_for_file(
-	git_oid *out, git_diff *, const char *, uint16_t, git_off_t);
-extern int git_diff__oid_for_entry(
-	git_oid *out, git_diff *, const git_index_entry *, uint16_t, const git_oid *update);
-
-extern int git_diff__from_iterators(
-	git_diff **diff_ptr,
-	git_repository *repo,
-	git_iterator *old_iter,
-	git_iterator *new_iter,
-	const git_diff_options *opts);
-
-extern int git_diff__paired_foreach(
-	git_diff *idx2head,
-	git_diff *wd2idx,
-	int (*cb)(git_diff_delta *i2h, git_diff_delta *w2i, void *payload),
-	void *payload);
-
-extern int git_diff_find_similar__hashsig_for_file(
-	void **out, const git_diff_file *f, const char *path, void *p);
-
-extern int git_diff_find_similar__hashsig_for_buf(
-	void **out, const git_diff_file *f, const char *buf, size_t len, void *p);
-
-extern void git_diff_find_similar__hashsig_free(void *sig, void *payload);
-
-extern int git_diff_find_similar__calc_similarity(
-	int *score, void *siga, void *sigb, void *payload);
-
-extern int git_diff__commit(
-	git_diff **diff, git_repository *repo, const git_commit *commit, const git_diff_options *opts);
-
-/* Merge two `git_diff`s according to the callback given by `cb`. */
-
-typedef git_diff_delta *(*git_diff__merge_cb)(
-	const git_diff_delta *left,
-	const git_diff_delta *right,
-	git_pool *pool);
-
-extern int git_diff__merge(
-	git_diff *onto, const git_diff *from, git_diff__merge_cb cb);
-
-extern git_diff_delta *git_diff__merge_like_cgit(
-	const git_diff_delta *a,
-	const git_diff_delta *b,
-	git_pool *pool);
-
-/* Duplicate a `git_diff_delta` out of the `git_pool` */
-extern git_diff_delta *git_diff__delta_dup(
-	const git_diff_delta *d, git_pool *pool);
-
-/*
- * Sometimes a git_diff_file will have a zero size; this attempts to
- * fill in the size without loading the blob if possible.  If that is
- * not possible, then it will return the git_odb_object that had to be
- * loaded and the caller can use it or dispose of it as needed.
- */
-GIT_INLINE(int) git_diff_file__resolve_zero_size(
-	git_diff_file *file, git_odb_object **odb_obj, git_repository *repo)
-{
-	int error;
-	git_odb *odb;
-	size_t len;
-	git_otype type;
-
-	if ((error = git_repository_odb(&odb, repo)) < 0)
-		return error;
-
-	error = git_odb__read_header_or_object(
-		odb_obj, &len, &type, odb, &file->id);
-
-	git_odb_free(odb);
-
-	if (!error)
-		file->size = (git_off_t)len;
+extern int git_diff_delta__cmp(const void *a, const void *b);
+extern int git_diff_delta__casecmp(const void *a, const void *b);
 
-	return error;
-}
+extern int git_diff__entry_cmp(const void *a, const void *b);
+extern int git_diff__entry_icmp(const void *a, const void *b);
 
 #endif
 

src/diff_driver.c

@@ -9,7 +9,6 @@
 #include "git2/attr.h"
 
 #include "diff.h"
-#include "diff_patch.h"
 #include "diff_driver.h"
 #include "strmap.h"
 #include "map.h"

src/diff_file.c

@@ -8,6 +8,7 @@
 #include "git2/blob.h"
 #include "git2/submodule.h"
 #include "diff.h"
+#include "diff_generate.h"
 #include "diff_file.h"
 #include "odb.h"
 #include "fileops.h"
@@ -149,12 +150,14 @@ int git_diff_file_content__init_from_src(
 		if (src->blob) {
 			fc->file->size = git_blob_rawsize(src->blob);
 			git_oid_cpy(&fc->file->id, git_blob_id(src->blob));
+			fc->file->id_abbrev = GIT_OID_HEXSZ;
 
 			fc->map.len  = (size_t)fc->file->size;
 			fc->map.data = (char *)git_blob_rawcontent(src->blob);
 		} else {
 			fc->file->size = src->buflen;
 			git_odb_hash(&fc->file->id, src->buf, src->buflen, GIT_OBJ_BLOB);
+			fc->file->id_abbrev = GIT_OID_HEXSZ;
 
 			fc->map.len  = src->buflen;
 			fc->map.data = (char *)src->buf;

src/diff_generate.h

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_generate_h__
+#define INCLUDE_diff_generate_h__
+
+enum {
+	GIT_DIFFCAPS_HAS_SYMLINKS     = (1 << 0), /* symlinks on platform? */
+	GIT_DIFFCAPS_IGNORE_STAT      = (1 << 1), /* use stat? */
+	GIT_DIFFCAPS_TRUST_MODE_BITS  = (1 << 2), /* use st_mode? */
+	GIT_DIFFCAPS_TRUST_CTIME      = (1 << 3), /* use st_ctime? */
+	GIT_DIFFCAPS_USE_DEV          = (1 << 4), /* use st_dev? */
+};
+
+#define DIFF_FLAGS_KNOWN_BINARY (GIT_DIFF_FLAG_BINARY|GIT_DIFF_FLAG_NOT_BINARY)
+#define DIFF_FLAGS_NOT_BINARY   (GIT_DIFF_FLAG_NOT_BINARY|GIT_DIFF_FLAG__NO_DATA)
+
+enum {
+	GIT_DIFF_FLAG__FREE_PATH  = (1 << 7),  /* `path` is allocated memory */
+	GIT_DIFF_FLAG__FREE_DATA  = (1 << 8),  /* internal file data is allocated */
+	GIT_DIFF_FLAG__UNMAP_DATA = (1 << 9),  /* internal file data is mmap'ed */
+	GIT_DIFF_FLAG__NO_DATA    = (1 << 10), /* file data should not be loaded */
+	GIT_DIFF_FLAG__FREE_BLOB  = (1 << 11), /* release the blob when done */
+	GIT_DIFF_FLAG__LOADED     = (1 << 12), /* file data has been loaded */
+
+	GIT_DIFF_FLAG__TO_DELETE  = (1 << 16), /* delete entry during rename det. */
+	GIT_DIFF_FLAG__TO_SPLIT   = (1 << 17), /* split entry during rename det. */
+	GIT_DIFF_FLAG__IS_RENAME_TARGET = (1 << 18),
+	GIT_DIFF_FLAG__IS_RENAME_SOURCE = (1 << 19),
+	GIT_DIFF_FLAG__HAS_SELF_SIMILARITY = (1 << 20),
+};
+
+#define GIT_DIFF_FLAG__CLEAR_INTERNAL(F) (F) = ((F) & 0x00FFFF)
+
+#define GIT_DIFF__VERBOSE  (1 << 30)
+
+extern void git_diff_addref(git_diff *diff);
+
+extern bool git_diff_delta__should_skip(
+	const git_diff_options *opts, const git_diff_delta *delta);
+
+extern int git_diff__from_iterators(
+	git_diff **diff_ptr,
+	git_repository *repo,
+	git_iterator *old_iter,
+	git_iterator *new_iter,
+	const git_diff_options *opts);
+
+extern int git_diff__commit(
+	git_diff **diff, git_repository *repo, const git_commit *commit, const git_diff_options *opts);
+
+extern int git_diff__paired_foreach(
+	git_diff *idx2head,
+	git_diff *wd2idx,
+	int (*cb)(git_diff_delta *i2h, git_diff_delta *w2i, void *payload),
+	void *payload);
+
+/* Merge two `git_diff`s according to the callback given by `cb`. */
+
+typedef git_diff_delta *(*git_diff__merge_cb)(
+	const git_diff_delta *left,
+	const git_diff_delta *right,
+	git_pool *pool);
+
+extern int git_diff__merge(
+	git_diff *onto, const git_diff *from, git_diff__merge_cb cb);
+
+extern git_diff_delta *git_diff__merge_like_cgit(
+	const git_diff_delta *a,
+	const git_diff_delta *b,
+	git_pool *pool);
+
+/* Duplicate a `git_diff_delta` out of the `git_pool` */
+extern git_diff_delta *git_diff__delta_dup(
+	const git_diff_delta *d, git_pool *pool);
+
+extern int git_diff__oid_for_file(
+	git_oid *out,
+	git_diff *diff,
+	const char *path,
+	uint16_t mode,
+	git_off_t size);
+
+extern int git_diff__oid_for_entry(
+	git_oid *out,
+	git_diff *diff,
+	const git_index_entry *src,
+	uint16_t mode,
+	const git_oid *update_match);
+
+/*
+ * Sometimes a git_diff_file will have a zero size; this attempts to
+ * fill in the size without loading the blob if possible.  If that is
+ * not possible, then it will return the git_odb_object that had to be
+ * loaded and the caller can use it or dispose of it as needed.
+ */
+GIT_INLINE(int) git_diff_file__resolve_zero_size(
+	git_diff_file *file, git_odb_object **odb_obj, git_repository *repo)
+{
+	int error;
+	git_odb *odb;
+	size_t len;
+	git_otype type;
+
+	if ((error = git_repository_odb(&odb, repo)) < 0)
+		return error;
+
+	error = git_odb__read_header_or_object(
+		odb_obj, &len, &type, odb, &file->id);
+
+	git_odb_free(odb);
+
+	if (!error)
+		file->size = (git_off_t)len;
+
+	return error;
+}
+
+#endif
+

src/diff_parse.c

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#include "common.h"
+#include "diff.h"
+#include "patch.h"
+#include "patch_parse.h"
+
+typedef struct {
+	struct git_diff base;
+
+	git_vector patches;
+} git_diff_parsed;
+
+static void diff_parsed_free(git_diff *d)
+{
+	git_diff_parsed *diff = (git_diff_parsed *)d;
+	git_patch *patch;
+	size_t i;
+
+	git_vector_foreach(&diff->patches, i, patch)
+		git_patch_free(patch);
+
+	git_vector_free(&diff->patches);
+
+	git_vector_free(&diff->base.deltas);
+	git_pool_clear(&diff->base.pool);
+
+	git__memzero(diff, sizeof(*diff));
+	git__free(diff);
+}
+
+static git_diff_parsed *diff_parsed_alloc(void)
+{
+	git_diff_parsed *diff;
+
+	if ((diff = git__calloc(1, sizeof(git_diff_parsed))) == NULL)
+		return NULL;
+
+	GIT_REFCOUNT_INC(diff);
+	diff->base.type = GIT_DIFF_TYPE_PARSED;
+	diff->base.opts.flags &= ~GIT_DIFF_IGNORE_CASE;
+	diff->base.strcomp = git__strcmp;
+	diff->base.strncomp = git__strncmp;
+	diff->base.pfxcomp = git__prefixcmp;
+	diff->base.entrycomp = git_diff__entry_cmp;
+	diff->base.free_fn = diff_parsed_free;
+
+	git_pool_init(&diff->base.pool, 1);
+
+	if (git_vector_init(&diff->patches, 0, NULL) < 0 ||
+		git_vector_init(&diff->base.deltas, 0, git_diff_delta__cmp) < 0) {
+		git_diff_free(&diff->base);
+		return NULL;
+	}
+
+	git_vector_set_cmp(&diff->base.deltas, git_diff_delta__cmp);
+
+	return diff;
+}
+
+int git_diff_from_buffer(
+	git_diff **out,
+	const char *content,
+	size_t content_len)
+{
+	git_diff_parsed *diff;
+	git_patch *patch;
+	git_patch_parse_ctx *ctx = NULL;
+	int error = 0;
+
+	*out = NULL;
+
+	diff = diff_parsed_alloc();
+	GITERR_CHECK_ALLOC(diff);
+
+	ctx = git_patch_parse_ctx_init(content, content_len, NULL);
+	GITERR_CHECK_ALLOC(ctx);
+
+	while (ctx->remain_len) {
+		if ((error = git_patch_parse(&patch, ctx)) < 0)
+			break;
+
+		git_vector_insert(&diff->patches, patch);
+		git_vector_insert(&diff->base.deltas, patch->delta);
+	}
+
+	if (error == GIT_ENOTFOUND && git_vector_length(&diff->patches) > 0) {
+		giterr_clear();
+		error = 0;
+	}
+
+	git_patch_parse_ctx_free(ctx);
+
+	if (error < 0)
+		git_diff_free(&diff->base);
+	else
+		*out = &diff->base;
+
+	return error;
+}
+

src/diff_stats.c

@@ -7,7 +7,7 @@
 #include "common.h"
 #include "vector.h"
 #include "diff.h"
-#include "diff_patch.h"
+#include "patch_generate.h"
 
 #define DIFF_RENAME_FILE_SEPARATOR " => "
 #define STATS_FULL_MIN_SCALE 7
@@ -190,8 +190,9 @@ int git_diff_get_stats(
 			break;
 
 		/* keep a count of renames because it will affect formatting */
-		delta = git_patch_get_delta(patch);
+		delta = patch->delta;
 
+		/* TODO ugh */
 		namelen = strlen(delta->new_file.path);
 		if (strcmp(delta->old_file.path, delta->new_file.path) != 0) {
 			namelen += strlen(delta->old_file.path);

src/diff_tform.c

@@ -11,6 +11,7 @@
 #include "git2/sys/hashsig.h"
 
 #include "diff.h"
+#include "diff_generate.h"
 #include "path.h"
 #include "fileops.h"
 #include "config.h"

src/diff_tform.h

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_diff_tform_h__
+#define INCLUDE_diff_tform_h__
+
+extern int git_diff_find_similar__hashsig_for_file(
+	void **out, const git_diff_file *f, const char *path, void *p);
+
+extern int git_diff_find_similar__hashsig_for_buf(
+	void **out, const git_diff_file *f, const char *buf, size_t len, void *p);
+
+extern void git_diff_find_similar__hashsig_free(void *sig, void *payload);
+
+extern int git_diff_find_similar__calc_similarity(
+	int *score, void *siga, void *sigb, void *payload);
+
+#endif
+

src/diff_xdiff.c

@@ -8,8 +8,8 @@
 #include "common.h"
 #include "diff.h"
 #include "diff_driver.h"
-#include "diff_patch.h"
 #include "diff_xdiff.h"
+#include "patch_generate.h"
 
 static int git_xdiff_scan_int(const char **str, int *value)
 {
@@ -56,7 +56,7 @@ fail:
 
 typedef struct {
 	git_xdiff_output *xo;
-	git_patch *patch;
+	git_patch_generated *patch;
 	git_diff_hunk hunk;
 	int old_lineno, new_lineno;
 	mmfile_t xd_old_data, xd_new_data;
@@ -110,9 +110,9 @@ static int diff_update_lines(
 static int git_xdiff_cb(void *priv, mmbuffer_t *bufs, int len)
 {
 	git_xdiff_info *info = priv;
-	git_patch *patch = info->patch;
-	const git_diff_delta *delta = git_patch_get_delta(patch);
-	git_diff_output *output = &info->xo->output;
+	git_patch_generated *patch = info->patch;
+	const git_diff_delta *delta = patch->base.delta;
+	git_patch_generated_output *output = &info->xo->output;
 	git_diff_line line;
 
 	if (len == 1) {
@@ -181,7 +181,7 @@ static int git_xdiff_cb(void *priv, mmbuffer_t *bufs, int len)
 	return output->error;
 }
 
-static int git_xdiff(git_diff_output *output, git_patch *patch)
+static int git_xdiff(git_patch_generated_output *output, git_patch_generated *patch)
 {
 	git_xdiff_output *xo = (git_xdiff_output *)output;
 	git_xdiff_info info;
@@ -194,7 +194,7 @@ static int git_xdiff(git_diff_output *output, git_patch *patch)
 	xo->callback.priv = &info;
 
 	git_diff_find_context_init(
-		&xo->config.find_func, &findctxt, git_patch__driver(patch));
+		&xo->config.find_func, &findctxt, git_patch_generated_driver(patch));
 	xo->config.find_func_priv = &findctxt;
 
 	if (xo->config.find_func != NULL)
@@ -206,8 +206,8 @@ static int git_xdiff(git_diff_output *output, git_patch *patch)
 	 * updates are needed to xo->params.flags
 	 */
 
-	git_patch__old_data(&info.xd_old_data.ptr, &info.xd_old_data.size, patch);
-	git_patch__new_data(&info.xd_new_data.ptr, &info.xd_new_data.size, patch);
+	git_patch_generated_old_data(&info.xd_old_data.ptr, &info.xd_old_data.size, patch);
+	git_patch_generated_new_data(&info.xd_new_data.ptr, &info.xd_new_data.size, patch);
 
 	if (info.xd_old_data.size > GIT_XDIFF_MAX_SIZE ||
 		info.xd_new_data.size > GIT_XDIFF_MAX_SIZE) {

src/diff_xdiff.h

@@ -8,20 +8,20 @@
 #define INCLUDE_diff_xdiff_h__
 
 #include "diff.h"
-#include "diff_patch.h"
 #include "xdiff/xdiff.h"
+#include "patch_generate.h"
 
 /* xdiff cannot cope with large files.  these files should not be passed to
  * xdiff.  callers should treat these large files as binary.
  */
 #define GIT_XDIFF_MAX_SIZE (1024LL * 1024 * 1023)
 
-/* A git_xdiff_output is a git_diff_output with extra fields necessary
- * to use libxdiff.  Calling git_xdiff_init() will set the diff_cb field
- * of the output to use xdiff to generate the diffs.
+/* A git_xdiff_output is a git_patch_generate_output with extra fields
+ * necessary to use libxdiff.  Calling git_xdiff_init() will set the diff_cb
+ * field of the output to use xdiff to generate the diffs.
  */
 typedef struct {
-	git_diff_output output;
+	git_patch_generated_output output;
 
 	xdemitconf_t config;
 	xpparam_t    params;

src/merge.c

@@ -18,6 +18,8 @@
 #include "iterator.h"
 #include "refs.h"
 #include "diff.h"
+#include "diff_generate.h"
+#include "diff_tform.h"
 #include "checkout.h"
 #include "tree.h"
 #include "blob.h"

src/odb.c

@@ -12,7 +12,7 @@
 #include "fileops.h"
 #include "hash.h"
 #include "odb.h"
-#include "delta-apply.h"
+#include "delta.h"
 #include "filter.h"
 #include "repository.h"
 

src/odb_loose.c

@@ -12,7 +12,7 @@
 #include "fileops.h"
 #include "hash.h"
 #include "odb.h"
-#include "delta-apply.h"
+#include "delta.h"
 #include "filebuf.h"
 
 #include "git2/odb_backend.h"

src/odb_pack.c

@@ -13,7 +13,7 @@
 #include "fileops.h"
 #include "hash.h"
 #include "odb.h"
-#include "delta-apply.h"
+#include "delta.h"
 #include "sha1_lookup.h"
 #include "mwindow.h"
 #include "pack.h"

src/pack-objects.c

@@ -144,7 +144,7 @@ int git_packbuilder_new(git_packbuilder **out, git_repository *repo)
 	pb->nr_threads = 1; /* do not spawn any thread by default */
 
 	if (git_hash_ctx_init(&pb->ctx) < 0 ||
-		git_zstream_init(&pb->zstream) < 0 ||
+		git_zstream_init(&pb->zstream, GIT_ZSTREAM_DEFLATE) < 0 ||
 		git_repository_odb(&pb->odb, repo) < 0 ||
 		packbuilder_config(pb) < 0)
 		goto on_error;
@@ -274,6 +274,7 @@ static int get_delta(void **out, git_odb *odb, git_pobject *po)
 	git_odb_object *src = NULL, *trg = NULL;
 	unsigned long delta_size;
 	void *delta_buf;
+	int error;
 
 	*out = NULL;
 
@@ -281,12 +282,15 @@ static int get_delta(void **out, git_odb *odb, git_pobject *po)
 	    git_odb_read(&trg, odb, &po->id) < 0)
 		goto on_error;
 
-	delta_buf = git_delta(
-		git_odb_object_data(src), (unsigned long)git_odb_object_size(src),
-		git_odb_object_data(trg), (unsigned long)git_odb_object_size(trg),
-		&delta_size, 0);
+	error = git_delta(&delta_buf, &delta_size,
+		git_odb_object_data(src), git_odb_object_size(src),
+		git_odb_object_data(trg), git_odb_object_size(trg),
+		0);
+
+	if (error < 0 && error != GIT_EBUFS)
+		goto on_error;
 
-	if (!delta_buf || delta_size != po->delta_size) {
+	if (error == GIT_EBUFS || delta_size != po->delta_size) {
 		giterr_set(GITERR_INVALID, "Delta size changed");
 		goto on_error;
 	}
@@ -815,16 +819,14 @@ static int try_delta(git_packbuilder *pb, struct unpacked *trg,
 		*mem_usage += sz;
 	}
 	if (!src->index) {
-		src->index = git_delta_create_index(src->data, src_size);
-		if (!src->index)
+		if (git_delta_index_init(&src->index, src->data, src_size) < 0)
 			return 0; /* suboptimal pack - out of memory */
 
-		*mem_usage += git_delta_sizeof_index(src->index);
+		*mem_usage += git_delta_index_size(src->index);
 	}
 
-	delta_buf = git_delta_create(src->index, trg->data, trg_size,
-				     &delta_size, max_size);
-	if (!delta_buf)
+	if (git_delta_create_from_index(&delta_buf, &delta_size, src->index, trg->data, trg_size,
+		max_size) < 0)
 		return 0;
 
 	if (trg_object->delta) {
@@ -885,9 +887,14 @@ static unsigned int check_delta_limit(git_pobject *me, unsigned int n)
 
 static unsigned long free_unpacked(struct unpacked *n)
 {
-	unsigned long freed_mem = git_delta_sizeof_index(n->index);
-	git_delta_free_index(n->index);
+	unsigned long freed_mem = 0;
+
+	if (n->index) {
+		freed_mem += git_delta_index_size(n->index);
+		git_delta_index_free(n->index);
+	}
 	n->index = NULL;
+
 	if (n->data) {
 		freed_mem += (unsigned long)n->object->size;
 		git__free(n->data);

src/pack.c

@@ -8,7 +8,7 @@
 #include "common.h"
 #include "odb.h"
 #include "pack.h"
-#include "delta-apply.h"
+#include "delta.h"
 #include "sha1_lookup.h"
 #include "mwindow.h"
 #include "fileops.h"
@@ -505,7 +505,7 @@ int git_packfile_resolve_header(
 		git_mwindow_close(&w_curs);
 		if ((error = git_packfile_stream_open(&stream, p, curpos)) < 0)
 			return error;
-		error = git__delta_read_header_fromstream(&base_size, size_p, &stream);
+		error = git_delta_read_header_fromstream(&base_size, size_p, &stream);
 		git_packfile_stream_free(&stream);
 		if (error < 0)
 			return error;
@@ -730,8 +730,9 @@ int git_packfile_unpack(
 		obj->len = 0;
 		obj->type = GIT_OBJ_BAD;
 
-		error = git__delta_apply(obj, base.data, base.len, delta.data, delta.len);
+		error = git_delta_apply(&obj->data, &obj->len, base.data, base.len, delta.data, delta.len);
 		obj->type = base_type;
+
 		/*
 		 * We usually don't want to free the base at this
 		 * point, as we put it into the cache in the previous

src/patch.c

+#include "git2/patch.h"
+#include "diff.h"
+#include "patch.h"
+
+
+int git_patch__invoke_callbacks(
+	git_patch *patch,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload)
+{
+	int error = 0;
+	uint32_t i, j;
+
+	if (file_cb)
+		error = file_cb(patch->delta, 0, payload);
+
+	if ((patch->delta->flags & GIT_DIFF_FLAG_BINARY) != 0) {
+		if (binary_cb)
+			error = binary_cb(patch->delta, &patch->binary, payload);
+
+		return error;
+	}
+
+	if (!hunk_cb && !line_cb)
+		return error;
+
+	for (i = 0; !error && i < git_array_size(patch->hunks); ++i) {
+		git_patch_hunk *h = git_array_get(patch->hunks, i);
+
+		if (hunk_cb)
+			error = hunk_cb(patch->delta, &h->hunk, payload);
+
+		if (!line_cb)
+			continue;
+
+		for (j = 0; !error && j < h->line_count; ++j) {
+			git_diff_line *l =
+				git_array_get(patch->lines, h->line_start + j);
+
+			error = line_cb(patch->delta, &h->hunk, l, payload);
+		}
+	}
+
+	return error;
+}
+
+size_t git_patch_size(
+	git_patch *patch,
+	int include_context,
+	int include_hunk_headers,
+	int include_file_headers)
+{
+	size_t out;
+
+	assert(patch);
+
+	out = patch->content_size;
+
+	if (!include_context)
+		out -= patch->context_size;
+
+	if (include_hunk_headers)
+		out += patch->header_size;
+
+	if (include_file_headers) {
+		git_buf file_header = GIT_BUF_INIT;
+
+		if (git_diff_delta__format_file_header(
+			&file_header, patch->delta, NULL, NULL, 0) < 0)
+			giterr_clear();
+		else
+			out += git_buf_len(&file_header);
+
+		git_buf_free(&file_header);
+	}
+
+	return out;
+}
+
+int git_patch_line_stats(
+	size_t *total_ctxt,
+	size_t *total_adds,
+	size_t *total_dels,
+	const git_patch *patch)
+{
+	size_t totals[3], idx;
+
+	memset(totals, 0, sizeof(totals));
+
+	for (idx = 0; idx < git_array_size(patch->lines); ++idx) {
+		git_diff_line *line = git_array_get(patch->lines, idx);
+		if (!line)
+			continue;
+
+		switch (line->origin) {
+		case GIT_DIFF_LINE_CONTEXT:  totals[0]++; break;
+		case GIT_DIFF_LINE_ADDITION: totals[1]++; break;
+		case GIT_DIFF_LINE_DELETION: totals[2]++; break;
+		default:
+			/* diff --stat and --numstat don't count EOFNL marks because
+			* they will always be paired with a ADDITION or DELETION line.
+			*/
+			break;
+		}
+	}
+
+	if (total_ctxt)
+		*total_ctxt = totals[0];
+	if (total_adds)
+		*total_adds = totals[1];
+	if (total_dels)
+		*total_dels = totals[2];
+
+	return 0;
+}
+
+const git_diff_delta *git_patch_get_delta(const git_patch *patch)
+{
+	assert(patch);
+	return patch->delta;
+}
+
+size_t git_patch_num_hunks(const git_patch *patch)
+{
+	assert(patch);
+	return git_array_size(patch->hunks);
+}
+
+static int patch_error_outofrange(const char *thing)
+{
+	giterr_set(GITERR_INVALID, "patch %s index out of range", thing);
+	return GIT_ENOTFOUND;
+}
+
+int git_patch_get_hunk(
+	const git_diff_hunk **out,
+	size_t *lines_in_hunk,
+	git_patch *patch,
+	size_t hunk_idx)
+{
+	git_patch_hunk *hunk;
+	assert(patch);
+
+	hunk = git_array_get(patch->hunks, hunk_idx);
+
+	if (!hunk) {
+		if (out) *out = NULL;
+		if (lines_in_hunk) *lines_in_hunk = 0;
+		return patch_error_outofrange("hunk");
+	}
+
+	if (out) *out = &hunk->hunk;
+	if (lines_in_hunk) *lines_in_hunk = hunk->line_count;
+	return 0;
+}
+
+int git_patch_num_lines_in_hunk(const git_patch *patch, size_t hunk_idx)
+{
+	git_patch_hunk *hunk;
+	assert(patch);
+
+	if (!(hunk = git_array_get(patch->hunks, hunk_idx)))
+		return patch_error_outofrange("hunk");
+	return (int)hunk->line_count;
+}
+
+int git_patch_get_line_in_hunk(
+	const git_diff_line **out,
+	git_patch *patch,
+	size_t hunk_idx,
+	size_t line_of_hunk)
+{
+	git_patch_hunk *hunk;
+	git_diff_line *line;
+
+	assert(patch);
+
+	if (!(hunk = git_array_get(patch->hunks, hunk_idx))) {
+		if (out) *out = NULL;
+		return patch_error_outofrange("hunk");
+	}
+
+	if (line_of_hunk >= hunk->line_count ||
+		!(line = git_array_get(
+			patch->lines, hunk->line_start + line_of_hunk))) {
+		if (out) *out = NULL;
+		return patch_error_outofrange("line");
+	}
+
+	if (out) *out = line;
+	return 0;
+}
+
+static void git_patch__free(git_patch *patch)
+{
+	if (patch->free_fn)
+		patch->free_fn(patch);
+}
+
+void git_patch_free(git_patch *patch)
+{
+	if (patch)
+		GIT_REFCOUNT_DEC(patch, git_patch__free);
+}

src/patch.h

+/*
+* Copyright (C) the libgit2 contributors. All rights reserved.
+*
+* This file is part of libgit2, distributed under the GNU GPL v2 with
+* a Linking Exception. For full terms see the included COPYING file.
+*/
+#ifndef INCLUDE_patch_h__
+#define INCLUDE_patch_h__
+
+#include "git2/patch.h"
+#include "array.h"
+
+/* cached information about a hunk in a patch */
+typedef struct git_patch_hunk {
+	git_diff_hunk hunk;
+	size_t line_start;
+	size_t line_count;
+} git_patch_hunk;
+
+struct git_patch {
+	git_refcount rc;
+
+	git_repository *repo; /* may be null */
+
+	git_diff_options diff_opts;
+
+	git_diff_delta *delta;
+	git_diff_binary binary;
+	git_array_t(git_patch_hunk) hunks;
+	git_array_t(git_diff_line) lines;
+
+	size_t header_size;
+	size_t content_size;
+	size_t context_size;
+
+	void (*free_fn)(git_patch *patch);
+};
+
+extern int git_patch__invoke_callbacks(
+	git_patch *patch,
+	git_diff_file_cb file_cb,
+	git_diff_binary_cb binary_cb,
+	git_diff_hunk_cb hunk_cb,
+	git_diff_line_cb line_cb,
+	void *payload);
+
+extern int git_patch_line_stats(
+	size_t *total_ctxt,
+	size_t *total_adds,
+	size_t *total_dels,
+	const git_patch *patch);
+
+/** Options for parsing patch files. */
+typedef struct {
+	/**
+	 * The length of the prefix (in path segments) for the filenames.
+	 * This prefix will be removed when looking for files.  The default is 1.
+	 */
+	uint32_t prefix_len;
+} git_patch_options;
+
+#define GIT_PATCH_OPTIONS_INIT { 1 }
+
+extern void git_patch_free(git_patch *patch);
+
+#endif

src/diff_patch.h → src/patch_generate.h

@@ -4,66 +4,48 @@
  * This file is part of libgit2, distributed under the GNU GPL v2 with
  * a Linking Exception. For full terms see the included COPYING file.
  */
-#ifndef INCLUDE_diff_patch_h__
-#define INCLUDE_diff_patch_h__
+#ifndef INCLUDE_patch_generate_h__
+#define INCLUDE_patch_generate_h__
 
 #include "common.h"
 #include "diff.h"
 #include "diff_file.h"
-#include "array.h"
-#include "git2/patch.h"
-
- /* cached information about a hunk in a diff */
-typedef struct diff_patch_hunk {
-	git_diff_hunk hunk;
-	size_t line_start;
-	size_t line_count;
-} diff_patch_hunk;
+#include "patch.h"
 
 enum {
-	GIT_DIFF_PATCH_ALLOCATED = (1 << 0),
-	GIT_DIFF_PATCH_INITIALIZED = (1 << 1),
-	GIT_DIFF_PATCH_LOADED = (1 << 2),
+	GIT_PATCH_GENERATED_ALLOCATED = (1 << 0),
+	GIT_PATCH_GENERATED_INITIALIZED = (1 << 1),
+	GIT_PATCH_GENERATED_LOADED = (1 << 2),
 	/* the two sides are different */
-	GIT_DIFF_PATCH_DIFFABLE = (1 << 3),
+	GIT_PATCH_GENERATED_DIFFABLE = (1 << 3),
 	/* the difference between the two sides has been computed */
-	GIT_DIFF_PATCH_DIFFED = (1 << 4),
-	GIT_DIFF_PATCH_FLATTENED = (1 << 5),
+	GIT_PATCH_GENERATED_DIFFED = (1 << 4),
+	GIT_PATCH_GENERATED_FLATTENED = (1 << 5),
 };
 
-struct git_patch {
-	git_refcount rc;
+struct git_patch_generated {
+	struct git_patch base;
+
 	git_diff *diff; /* for refcount purposes, maybe NULL for blob diffs */
-	git_diff_options diff_opts;
-	git_diff_delta *delta;
 	size_t delta_index;
 	git_diff_file_content ofile;
 	git_diff_file_content nfile;
 	uint32_t flags;
-	git_diff_binary binary;
-	git_array_t(diff_patch_hunk) hunks;
-	git_array_t(git_diff_line)   lines;
-	size_t content_size, context_size, header_size;
 	git_pool flattened;
 };
 
-extern git_diff *git_patch__diff(git_patch *);
+typedef struct git_patch_generated git_patch_generated;
 
-extern git_diff_driver *git_patch__driver(git_patch *);
+extern git_diff_driver *git_patch_generated_driver(git_patch_generated *);
 
-extern void git_patch__old_data(char **, size_t *, git_patch *);
-extern void git_patch__new_data(char **, size_t *, git_patch *);
+extern void git_patch_generated_old_data(
+	char **, size_t *, git_patch_generated *);
+extern void git_patch_generated_new_data(
+	char **, size_t *, git_patch_generated *);
 
-extern int git_patch__invoke_callbacks(
-	git_patch *patch,
-	git_diff_file_cb file_cb,
-	git_diff_binary_cb binary_cb,
-	git_diff_hunk_cb hunk_cb,
-	git_diff_line_cb line_cb,
-	void *payload);
+typedef struct git_patch_generated_output git_patch_generated_output;
 
-typedef struct git_diff_output git_diff_output;
-struct git_diff_output {
+struct git_patch_generated_output {
 	/* these callbacks are issued with the diff data */
 	git_diff_file_cb file_cb;
 	git_diff_binary_cb binary_cb;
@@ -77,7 +59,8 @@ struct git_diff_output {
 	/* this callback is used to do the diff and drive the other callbacks.
 	 * see diff_xdiff.h for how to use this in practice for now.
 	 */
-	int (*diff_cb)(git_diff_output *output, git_patch *patch);
+	int (*diff_cb)(git_patch_generated_output *output,
+		git_patch_generated *patch);
 };
 
 #endif

src/patch_parse.h

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_patch_parse_h__
+#define INCLUDE_patch_parse_h__
+
+typedef struct {
+	git_refcount rc;
+
+	/* Original content buffer */
+	const char *content;
+	size_t content_len;
+
+	git_patch_options opts;
+
+	/* The remaining (unparsed) buffer */
+	const char *remain;
+	size_t remain_len;
+
+	const char *line;
+	size_t line_len;
+	size_t line_num;
+} git_patch_parse_ctx;
+
+extern git_patch_parse_ctx *git_patch_parse_ctx_init(
+	const char *content,
+	size_t content_len,
+	const git_patch_options *opts);
+
+extern void git_patch_parse_ctx_free(git_patch_parse_ctx *ctx);
+
+/**
+ * Create a patch for a single file from the contents of a patch buffer.
+ *
+ * @param out The patch to be created
+ * @param contents The contents of a patch file
+ * @param contents_len The length of the patch file
+ * @param opts The git_patch_options
+ * @return 0 on success, <0 on failure.
+ */
+extern int git_patch_from_buffer(
+	git_patch **out,
+	const char *contents,
+	size_t contents_len,
+	const git_patch_options *opts);
+
+extern int git_patch_parse(
+	git_patch **out,
+	git_patch_parse_ctx *ctx);
+
+#endif

src/path.c

@@ -306,6 +306,25 @@ int git_path_join_unrooted(
 	return 0;
 }
 
+void git_path_squash_slashes(git_buf *path)
+{
+	char *p, *q;
+
+	if (path->size == 0)
+		return;
+
+	for (p = path->ptr, q = path->ptr; *q; p++, q++) {
+		*p = *q;
+
+		while (*q == '/' && *(q+1) == '/') {
+			path->size--;
+			q++;
+		}
+	}
+
+	*p = '\0';
+}
+
 int git_path_prettify(git_buf *path_out, const char *path, const char *base)
 {
 	char buf[GIT_PATH_MAX];

src/path.h

@@ -244,6 +244,12 @@ extern int git_path_join_unrooted(
 	git_buf *path_out, const char *path, const char *base, ssize_t *root_at);
 
 /**
+ * Removes multiple occurrences of '/' in a row, squashing them into a
+ * single '/'.
+ */
+extern void git_path_squash_slashes(git_buf *path);
+
+/**
  * Clean up path, prepending base if it is not already rooted.
  */
 extern int git_path_prettify(git_buf *path_out, const char *path, const char *base);

src/stash.c

@@ -23,6 +23,7 @@
 #include "iterator.h"
 #include "merge.h"
 #include "diff.h"
+#include "diff_generate.h"
 
 static int create_error(int error, const char *msg)
 {

src/status.c

@@ -19,6 +19,7 @@
 
 #include "git2/diff.h"
 #include "diff.h"
+#include "diff_generate.h"
 
 static unsigned int index_delta2status(const git_diff_delta *head2idx)
 {

src/util.c

@@ -66,6 +66,12 @@ int git_strarray_copy(git_strarray *tgt, const git_strarray *src)
 
 int git__strtol64(int64_t *result, const char *nptr, const char **endptr, int base)
 {
+
+	return git__strntol64(result, nptr, (size_t)-1, endptr, base);
+}
+
+int git__strntol64(int64_t *result, const char *nptr, size_t nptr_len, const char **endptr, int base)
+{
 	const char *p;
 	int64_t n, nn;
 	int c, ovfl, v, neg, ndig;
@@ -111,7 +117,7 @@ int git__strtol64(int64_t *result, const char *nptr, const char **endptr, int ba
 	/*
 	 * Non-empty sequence of digits
 	 */
-	for (;; p++,ndig++) {
+	for (; nptr_len > 0; p++,ndig++,nptr_len--) {
 		c = *p;
 		v = base;
 		if ('0'<=c && c<='9')
@@ -148,11 +154,17 @@ Return:
 
 int git__strtol32(int32_t *result, const char *nptr, const char **endptr, int base)
 {
+
+	return git__strntol32(result, nptr, (size_t)-1, endptr, base);
+}
+
+int git__strntol32(int32_t *result, const char *nptr, size_t nptr_len, const char **endptr, int base)
+{
 	int error;
 	int32_t tmp_int;
 	int64_t tmp_long;
 
-	if ((error = git__strtol64(&tmp_long, nptr, endptr, base)) < 0)
+	if ((error = git__strntol64(&tmp_long, nptr, nptr_len, endptr, base)) < 0)
 		return error;
 
 	tmp_int = tmp_long & 0xFFFFFFFF;
@@ -321,6 +333,12 @@ char *git__strsep(char **end, const char *sep)
 	return NULL;
 }
 
+size_t git__linenlen(const char *buffer, size_t buffer_len)
+{
+	char *nl = memchr(buffer, '\n', buffer_len);
+	return nl ? (size_t)(nl - buffer) + 1 : buffer_len;
+}
+
 void git__hexdump(const char *buffer, size_t len)
 {
 	static const size_t LINE_WIDTH = 16;

src/util.h

@@ -263,7 +263,10 @@ GIT_INLINE(int) git__signum(int val)
 }
 
 extern int git__strtol32(int32_t *n, const char *buff, const char **end_buf, int base);
+extern int git__strntol32(int32_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
 extern int git__strtol64(int64_t *n, const char *buff, const char **end_buf, int base);
+extern int git__strntol64(int64_t *n, const char *buff, size_t buff_len, const char **end_buf, int base);
+
 
 extern void git__hexdump(const char *buffer, size_t n);
 extern uint32_t git__hash(const void *key, int len, uint32_t seed);
@@ -290,6 +293,8 @@ GIT_INLINE(int) git__tolower(int c)
 # define git__tolower(a) tolower(a)
 #endif
 
+extern size_t git__linenlen(const char *buffer, size_t buffer_len);
+
 GIT_INLINE(const char *) git__next_line(const char *s)
 {
 	while (*s && *s != '\n') s++;
@@ -466,6 +471,11 @@ GIT_INLINE(bool) git__iswildcard(int c)
 	return (c == '*' || c == '?' || c == '[');
 }
 
+GIT_INLINE(bool) git__isxdigit(int c)
+{
+	return ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'));
+}
+
 /*
  * Parse a string value as a boolean, just like Core Git does.
  *

src/vector.c

@@ -7,6 +7,7 @@
 
 #include "common.h"
 #include "vector.h"
+#include "integer.h"
 
 /* In elements, not bytes */
 #define MIN_ALLOCSIZE	8
@@ -330,6 +331,47 @@ int git_vector_resize_to(git_vector *v, size_t new_length)
 	return 0;
 }
 
+int git_vector_insert_null(git_vector *v, size_t idx, size_t insert_len)
+{
+	size_t new_length;
+
+	assert(insert_len > 0 && idx <= v->length);
+
+	GITERR_CHECK_ALLOC_ADD(&new_length, v->length, insert_len);
+
+	if (new_length > v->_alloc_size && resize_vector(v, new_length) < 0)
+		return -1;
+
+	memmove(&v->contents[idx + insert_len], &v->contents[idx],
+		sizeof(void *) * (v->length - idx));
+	memset(&v->contents[idx], 0, sizeof(void *) * insert_len);
+
+	v->length = new_length;
+	return 0;
+}
+
+int git_vector_remove_range(git_vector *v, size_t idx, size_t remove_len)
+{
+	size_t new_length = v->length - remove_len;
+	size_t end_idx = 0;
+	
+	assert(remove_len > 0);
+
+	if (git__add_sizet_overflow(&end_idx, idx, remove_len))
+		assert(0);
+
+	assert(end_idx <= v->length);
+
+	if (end_idx < v->length)
+		memmove(&v->contents[idx], &v->contents[end_idx],
+			sizeof(void *) * (v->length - end_idx));
+
+	memset(&v->contents[new_length], 0, sizeof(void *) * remove_len);
+
+	v->length = new_length;
+	return 0;
+}
+
 int git_vector_set(void **old, git_vector *v, size_t position, void *value)
 {
 	if (position + 1 > v->length) {

src/vector.h

@@ -93,6 +93,9 @@ void git_vector_remove_matching(
 	void *payload);
 
 int git_vector_resize_to(git_vector *v, size_t new_length);
+int git_vector_insert_null(git_vector *v, size_t idx, size_t insert_len);
+int git_vector_remove_range(git_vector *v, size_t idx, size_t remove_len);
+
 int git_vector_set(void **old, git_vector *v, size_t position, void *value);
 
 /** Check if vector is sorted */

src/zstream.c

@@ -28,20 +28,31 @@ static int zstream_seterr(git_zstream *zs)
 	return -1;
 }
 
-int git_zstream_init(git_zstream *zstream)
+int git_zstream_init(git_zstream *zstream, git_zstream_t type)
 {
-	zstream->zerr = deflateInit(&zstream->z, Z_DEFAULT_COMPRESSION);
+	zstream->type = type;
+
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		zstream->zerr = inflateInit(&zstream->z);
+	else
+		zstream->zerr = deflateInit(&zstream->z, Z_DEFAULT_COMPRESSION);
 	return zstream_seterr(zstream);
 }
 
 void git_zstream_free(git_zstream *zstream)
 {
-	deflateEnd(&zstream->z);
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		inflateEnd(&zstream->z);
+	else
+		deflateEnd(&zstream->z);
 }
 
 void git_zstream_reset(git_zstream *zstream)
 {
-	deflateReset(&zstream->z);
+	if (zstream->type == GIT_ZSTREAM_INFLATE)
+		inflateReset(&zstream->z);
+	else
+		deflateReset(&zstream->z);
 	zstream->in = NULL;
 	zstream->in_len = 0;
 	zstream->zerr = Z_STREAM_END;
@@ -75,6 +86,11 @@ int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream)
 	int zflush = Z_FINISH;
 	size_t out_remain = *out_len;
 
+	if (zstream->in_len && zstream->zerr == Z_STREAM_END) {
+		giterr_set(GITERR_ZLIB, "zlib input had trailing garbage");
+		return -1;
+	}
+
 	while (out_remain > 0 && zstream->zerr != Z_STREAM_END) {
 		size_t out_queued, in_queued, out_used, in_used;
 
@@ -97,7 +113,10 @@ int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream)
 		out_queued = (size_t)zstream->z.avail_out;
 
 		/* compress next chunk */
-		zstream->zerr = deflate(&zstream->z, zflush);
+		if (zstream->type == GIT_ZSTREAM_INFLATE)
+			zstream->zerr = inflate(&zstream->z, zflush);
+		else
+			zstream->zerr = deflate(&zstream->z, zflush);
 
 		if (zstream->zerr == Z_STREAM_ERROR)
 			return zstream_seterr(zstream);
@@ -120,12 +139,12 @@ int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream)
 	return 0;
 }
 
-int git_zstream_deflatebuf(git_buf *out, const void *in, size_t in_len)
+static int zstream_buf(git_buf *out, const void *in, size_t in_len, git_zstream_t type)
 {
 	git_zstream zs = GIT_ZSTREAM_INIT;
 	int error = 0;
 
-	if ((error = git_zstream_init(&zs)) < 0)
+	if ((error = git_zstream_init(&zs, type)) < 0)
 		return error;
 
 	if ((error = git_zstream_set_input(&zs, in, in_len)) < 0)
@@ -154,3 +173,13 @@ done:
 	git_zstream_free(&zs);
 	return error;
 }
+
+int git_zstream_deflatebuf(git_buf *out, const void *in, size_t in_len)
+{
+	return zstream_buf(out, in, in_len, GIT_ZSTREAM_DEFLATE);
+}
+
+int git_zstream_inflatebuf(git_buf *out, const void *in, size_t in_len)
+{
+	return zstream_buf(out, in, in_len, GIT_ZSTREAM_INFLATE);
+}

src/zstream.h

@@ -12,8 +12,14 @@
 #include "common.h"
 #include "buffer.h"
 
+typedef enum {
+	GIT_ZSTREAM_INFLATE,
+	GIT_ZSTREAM_DEFLATE,
+} git_zstream_t;
+
 typedef struct {
 	z_stream z;
+	git_zstream_t type;
 	const char *in;
 	size_t in_len;
 	int zerr;
@@ -21,7 +27,7 @@ typedef struct {
 
 #define GIT_ZSTREAM_INIT {{0}}
 
-int git_zstream_init(git_zstream *zstream);
+int git_zstream_init(git_zstream *zstream, git_zstream_t type);
 void git_zstream_free(git_zstream *zstream);
 
 int git_zstream_set_input(git_zstream *zstream, const void *in, size_t in_len);
@@ -35,5 +41,6 @@ bool git_zstream_done(git_zstream *zstream);
 void git_zstream_reset(git_zstream *zstream);
 
 int git_zstream_deflatebuf(git_buf *out, const void *in, size_t in_len);
+int git_zstream_inflatebuf(git_buf *out, const void *in, size_t in_len);
 
 #endif /* INCLUDE_zstream_h__ */

tests/apply/fromdiff.c

+#include "clar_libgit2.h"
+#include "git2/sys/repository.h"
+
+#include "apply.h"
+#include "repository.h"
+#include "buf_text.h"
+
+#include "../patch/patch_common.h"
+
+static git_repository *repo = NULL;
+static git_diff_options binary_opts = GIT_DIFF_OPTIONS_INIT;
+
+void test_apply_fromdiff__initialize(void)
+{
+	repo = cl_git_sandbox_init("renames");
+
+	binary_opts.flags |= GIT_DIFF_SHOW_BINARY;
+}
+
+void test_apply_fromdiff__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+static int apply_gitbuf(
+	const git_buf *old,
+	const char *oldname,
+	const git_buf *new,
+	const char *newname,
+	const char *patch_expected,
+	const git_diff_options *diff_opts)
+{
+	git_patch *patch;
+	git_buf result = GIT_BUF_INIT;
+	git_buf patchbuf = GIT_BUF_INIT;
+	char *filename;
+	unsigned int mode;
+	int error;
+
+	cl_git_pass(git_patch_from_buffers(&patch,
+		old ? old->ptr : NULL, old ? old->size : 0,
+		oldname,
+		new ? new->ptr : NULL, new ? new->size : 0,
+		newname,
+		diff_opts));
+
+	if (patch_expected) {
+		cl_git_pass(git_patch_to_buf(&patchbuf, patch));
+		cl_assert_equal_s(patch_expected, patchbuf.ptr);
+	}
+
+	error = git_apply__patch(&result, &filename, &mode, old ? old->ptr : NULL, old ? old->size : 0, patch);
+
+	if (error == 0 && new == NULL) {
+		cl_assert_equal_i(0, result.size);
+		cl_assert_equal_p(NULL, filename);
+		cl_assert_equal_i(0, mode);
+	}
+	else if (error == 0) {
+		cl_assert_equal_s(new->ptr, result.ptr);
+		cl_assert_equal_s(newname ? newname : oldname, filename);
+		cl_assert_equal_i(0100644, mode);
+	}
+
+	git__free(filename);
+	git_buf_free(&result);
+	git_buf_free(&patchbuf);
+	git_patch_free(patch);
+
+	return error;
+}
+
+static int apply_buf(
+	const char *old,
+	const char *oldname,
+	const char *new,
+	const char *newname,
+	const char *patch_expected,
+	const git_diff_options *diff_opts)
+{
+	git_buf o = GIT_BUF_INIT, n = GIT_BUF_INIT,
+		*optr = NULL, *nptr = NULL;
+
+	if (old) {
+		o.ptr = (char *)old;
+		o.size = strlen(old);
+		optr = &o;
+	}
+
+	if (new) {
+		n.ptr = (char *)new;
+		n.size = strlen(new);
+		nptr = &n;
+	}
+
+	return apply_gitbuf(optr, oldname, nptr, newname, patch_expected, diff_opts);
+}
+
+void test_apply_fromdiff__change_middle(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_CHANGE_MIDDLE, "file.txt",
+		PATCH_ORIGINAL_TO_CHANGE_MIDDLE, NULL));
+}
+
+void test_apply_fromdiff__change_middle_nocontext(void)
+{
+	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+	diff_opts.context_lines = 0;
+
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_CHANGE_MIDDLE, "file.txt",
+		PATCH_ORIGINAL_TO_CHANGE_MIDDLE_NOCONTEXT, &diff_opts));
+}
+
+void test_apply_fromdiff__change_firstline(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_CHANGE_FIRSTLINE, "file.txt",
+		PATCH_ORIGINAL_TO_CHANGE_FIRSTLINE, NULL));
+}
+
+void test_apply_fromdiff__lastline(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_CHANGE_LASTLINE, "file.txt",
+		PATCH_ORIGINAL_TO_CHANGE_LASTLINE, NULL));
+}
+
+void test_apply_fromdiff__prepend(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_PREPEND, "file.txt",
+		PATCH_ORIGINAL_TO_PREPEND, NULL));
+}
+
+void test_apply_fromdiff__prepend_nocontext(void)
+{
+	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+	diff_opts.context_lines = 0;
+
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_PREPEND, "file.txt",
+		PATCH_ORIGINAL_TO_PREPEND_NOCONTEXT, &diff_opts));
+}
+
+void test_apply_fromdiff__append(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_APPEND, "file.txt",
+		PATCH_ORIGINAL_TO_APPEND, NULL));
+}
+
+void test_apply_fromdiff__append_nocontext(void)
+{
+	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+	diff_opts.context_lines = 0;
+
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_APPEND, "file.txt",
+		PATCH_ORIGINAL_TO_APPEND_NOCONTEXT, &diff_opts));
+}
+
+void test_apply_fromdiff__prepend_and_append(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_PREPEND_AND_APPEND, "file.txt",
+		PATCH_ORIGINAL_TO_PREPEND_AND_APPEND, NULL));
+}
+
+void test_apply_fromdiff__to_empty_file(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		"", NULL,
+		PATCH_ORIGINAL_TO_EMPTY_FILE, NULL));
+}
+
+void test_apply_fromdiff__from_empty_file(void)
+{
+	cl_git_pass(apply_buf(
+		"", NULL,
+		FILE_ORIGINAL, "file.txt",
+		PATCH_EMPTY_FILE_TO_ORIGINAL, NULL));
+}
+
+void test_apply_fromdiff__add(void)
+{
+	cl_git_pass(apply_buf(
+		NULL, NULL,
+		FILE_ORIGINAL, "file.txt",
+		PATCH_ADD_ORIGINAL, NULL));
+}
+
+void test_apply_fromdiff__delete(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		NULL, NULL,
+		PATCH_DELETE_ORIGINAL, NULL));
+}
+
+void test_apply_fromdiff__no_change(void)
+{
+	cl_git_pass(apply_buf(
+		FILE_ORIGINAL, "file.txt",
+		FILE_ORIGINAL, "file.txt",
+		"", NULL));
+}
+
+void test_apply_fromdiff__binary_add(void)
+{
+	git_buf newfile = GIT_BUF_INIT;
+
+	newfile.ptr = FILE_BINARY_DELTA_MODIFIED;
+	newfile.size = FILE_BINARY_DELTA_MODIFIED_LEN;
+
+	cl_git_pass(apply_gitbuf(
+		NULL, NULL,
+		&newfile, "binary.bin",
+		NULL, &binary_opts));
+}
+
+void test_apply_fromdiff__binary_no_change(void)
+{
+	git_buf original = GIT_BUF_INIT;
+
+	original.ptr = FILE_BINARY_DELTA_ORIGINAL;
+	original.size = FILE_BINARY_DELTA_ORIGINAL_LEN;
+
+	cl_git_pass(apply_gitbuf(
+		&original, "binary.bin",
+		&original, "binary.bin",
+		"", &binary_opts));
+}
+
+void test_apply_fromdiff__binary_change_delta(void)
+{
+	git_buf original = GIT_BUF_INIT, modified = GIT_BUF_INIT;
+
+	original.ptr = FILE_BINARY_DELTA_ORIGINAL;
+	original.size = FILE_BINARY_DELTA_ORIGINAL_LEN;
+
+	modified.ptr = FILE_BINARY_DELTA_MODIFIED;
+	modified.size = FILE_BINARY_DELTA_MODIFIED_LEN;
+
+	cl_git_pass(apply_gitbuf(
+		&original, "binary.bin",
+		&modified, "binary.bin",
+		NULL, &binary_opts));
+}
+
+void test_apply_fromdiff__binary_change_literal(void)
+{
+	git_buf original = GIT_BUF_INIT, modified = GIT_BUF_INIT;
+
+	original.ptr = FILE_BINARY_LITERAL_ORIGINAL;
+	original.size = FILE_BINARY_LITERAL_ORIGINAL_LEN;
+
+	modified.ptr = FILE_BINARY_LITERAL_MODIFIED;
+	modified.size = FILE_BINARY_LITERAL_MODIFIED_LEN;
+
+	cl_git_pass(apply_gitbuf(
+		&original, "binary.bin",
+		&modified, "binary.bin",
+		NULL, &binary_opts));
+}
+
+void test_apply_fromdiff__binary_delete(void)
+{
+	git_buf original = GIT_BUF_INIT;
+
+	original.ptr = FILE_BINARY_DELTA_MODIFIED;
+	original.size = FILE_BINARY_DELTA_MODIFIED_LEN;
+
+	cl_git_pass(apply_gitbuf(
+		&original, "binary.bin",
+		NULL, NULL,
+		NULL, &binary_opts));
+}

tests/buf/quote.c

+#include "clar_libgit2.h"
+#include "buffer.h"
+
+static void expect_quote_pass(const char *expected, const char *str)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	cl_git_pass(git_buf_puts(&buf, str));
+	cl_git_pass(git_buf_quote(&buf));
+
+	cl_assert_equal_s(expected, git_buf_cstr(&buf));
+	cl_assert_equal_i(strlen(expected), git_buf_len(&buf));
+
+	git_buf_free(&buf);
+}
+
+void test_buf_quote__quote_succeeds(void)
+{
+	expect_quote_pass("", "");
+	expect_quote_pass("foo", "foo");
+	expect_quote_pass("foo/bar/baz.c", "foo/bar/baz.c");
+	expect_quote_pass("foo bar", "foo bar");
+	expect_quote_pass("\"\\\"leading quote\"", "\"leading quote");
+	expect_quote_pass("\"slash\\\\y\"", "slash\\y");
+	expect_quote_pass("\"foo\\r\\nbar\"", "foo\r\nbar");
+	expect_quote_pass("\"foo\\177bar\"", "foo\177bar");
+	expect_quote_pass("\"foo\\001bar\"", "foo\001bar");
+	expect_quote_pass("\"foo\\377bar\"", "foo\377bar");
+}
+
+static void expect_unquote_pass(const char *expected, const char *quoted)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	cl_git_pass(git_buf_puts(&buf, quoted));
+	cl_git_pass(git_buf_unquote(&buf));
+
+	cl_assert_equal_s(expected, git_buf_cstr(&buf));
+	cl_assert_equal_i(strlen(expected), git_buf_len(&buf));
+
+	git_buf_free(&buf);
+}
+
+static void expect_unquote_fail(const char *quoted)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	cl_git_pass(git_buf_puts(&buf, quoted));
+	cl_git_fail(git_buf_unquote(&buf));
+
+	git_buf_free(&buf);
+}
+
+void test_buf_quote__unquote_succeeds(void)
+{
+	expect_unquote_pass("", "\"\"");
+	expect_unquote_pass(" ", "\" \"");
+	expect_unquote_pass("foo", "\"foo\"");
+	expect_unquote_pass("foo bar", "\"foo bar\"");
+	expect_unquote_pass("foo\"bar", "\"foo\\\"bar\"");
+	expect_unquote_pass("foo\\bar", "\"foo\\\\bar\"");
+	expect_unquote_pass("foo\tbar", "\"foo\\tbar\"");
+	expect_unquote_pass("\vfoo\tbar\n", "\"\\vfoo\\tbar\\n\"");
+	expect_unquote_pass("foo\nbar", "\"foo\\012bar\"");
+	expect_unquote_pass("foo\r\nbar", "\"foo\\015\\012bar\"");
+	expect_unquote_pass("foo\r\nbar", "\"\\146\\157\\157\\015\\012\\142\\141\\162\"");
+	expect_unquote_pass("newline: \n", "\"newline: \\012\"");
+	expect_unquote_pass("0xff: \377", "\"0xff: \\377\"");
+}
+
+void test_buf_quote__unquote_fails(void)
+{
+	expect_unquote_fail("no quotes at all");
+	expect_unquote_fail("\"no trailing quote");
+	expect_unquote_fail("no leading quote\"");
+	expect_unquote_fail("\"invalid \\z escape char\"");
+	expect_unquote_fail("\"\\q invalid escape char\"");
+	expect_unquote_fail("\"invalid escape char \\p\"");
+	expect_unquote_fail("\"invalid \\1 escape char \"");
+	expect_unquote_fail("\"invalid \\14 escape char \"");
+	expect_unquote_fail("\"invalid \\280 escape char\"");
+	expect_unquote_fail("\"invalid \\378 escape char\"");
+	expect_unquote_fail("\"invalid \\380 escape char\"");
+	expect_unquote_fail("\"invalid \\411 escape char\"");
+	expect_unquote_fail("\"truncated escape char \\\"");
+	expect_unquote_fail("\"truncated escape char \\0\"");
+	expect_unquote_fail("\"truncated escape char \\01\"");
+}

tests/core/buffer.c

@@ -813,6 +813,44 @@ void test_core_buffer__encode_base85(void)
 	git_buf_free(&buf);
 }
 
+void test_core_buffer__decode_base85(void)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	cl_git_pass(git_buf_decode_base85(&buf, "bZBXF", 5, 4));
+	cl_assert_equal_sz(4, buf.size);
+	cl_assert_equal_s("this", buf.ptr);
+	git_buf_clear(&buf);
+
+	cl_git_pass(git_buf_decode_base85(&buf, "ba!tca&BaE", 10, 8));
+	cl_assert_equal_sz(8, buf.size);
+	cl_assert_equal_s("two rnds", buf.ptr);
+	git_buf_clear(&buf);
+
+	cl_git_pass(git_buf_decode_base85(&buf, "bZBXFAZc?TVqtS-AUHK3Wo~0{WMyOk", 30, 23));
+	cl_assert_equal_sz(23, buf.size);
+	cl_assert_equal_s("this is base 85 encoded", buf.ptr);
+	git_buf_clear(&buf);
+
+	git_buf_free(&buf);
+}
+
+void test_core_buffer__decode_base85_fails_gracefully(void)
+{
+	git_buf buf = GIT_BUF_INIT;
+
+	git_buf_puts(&buf, "foobar");
+
+	cl_git_fail(git_buf_decode_base85(&buf, "invalid charsZZ", 15, 42));
+	cl_git_fail(git_buf_decode_base85(&buf, "invalidchars__ ", 15, 42));
+	cl_git_fail(git_buf_decode_base85(&buf, "overflowZZ~~~~~", 15, 42));
+	cl_git_fail(git_buf_decode_base85(&buf, "truncated", 9, 42));
+	cl_assert_equal_sz(6, buf.size);
+	cl_assert_equal_s("foobar", buf.ptr);
+
+	git_buf_free(&buf);
+}
+
 void test_core_buffer__classify_with_utf8(void)
 {
 	char *data0 = "Simple text\n";

tests/core/vector.c

@@ -274,3 +274,105 @@ void test_core_vector__remove_matching(void)
 
 	git_vector_free(&x);
 }
+
+static void assert_vector(git_vector *x, void *expected[], size_t len)
+{
+	size_t i;
+
+	cl_assert_equal_i(len, x->length);
+
+	for (i = 0; i < len; i++)
+		cl_assert(expected[i] == x->contents[i]);
+}
+
+void test_core_vector__grow_and_shrink(void)
+{
+	git_vector x = GIT_VECTOR_INIT;
+	void *expected1[] = {
+		(void *)0x02, (void *)0x03, (void *)0x04, (void *)0x05,
+		(void *)0x06, (void *)0x07, (void *)0x08, (void *)0x09,
+		(void *)0x0a
+	};
+	void *expected2[] = {
+		(void *)0x02, (void *)0x04, (void *)0x05, (void *)0x06,
+		(void *)0x07, (void *)0x08, (void *)0x09, (void *)0x0a
+	};
+	void *expected3[] = {
+		(void *)0x02, (void *)0x04, (void *)0x05, (void *)0x06,
+		(void *)0x0a
+	};
+	void *expected4[] = {
+		(void *)0x02, (void *)0x04, (void *)0x05
+	};
+	void *expected5[] = {
+		(void *)0x00, (void *)0x00, (void *)0x02, (void *)0x04,
+		(void *)0x05
+	};
+	void *expected6[] = {
+		(void *)0x00, (void *)0x00, (void *)0x02, (void *)0x04,
+		(void *)0x05, (void *)0x00
+	};
+	void *expected7[] = {
+		(void *)0x00, (void *)0x00, (void *)0x02, (void *)0x04,
+		(void *)0x00, (void *)0x00, (void *)0x00, (void *)0x05,
+		(void *)0x00
+	};
+	void *expected8[] = {
+		(void *)0x04, (void *)0x00, (void *)0x00, (void *)0x00,
+		(void *)0x05, (void *)0x00
+	};
+	void *expected9[] = {
+		(void *)0x04, (void *)0x00, (void *)0x05, (void *)0x00
+	};
+	void *expectedA[] = { (void *)0x04, (void *)0x00 };
+	void *expectedB[] = { (void *)0x04 };
+
+	git_vector_insert(&x, (void *)0x01);
+	git_vector_insert(&x, (void *)0x02);
+	git_vector_insert(&x, (void *)0x03);
+	git_vector_insert(&x, (void *)0x04);
+	git_vector_insert(&x, (void *)0x05);
+	git_vector_insert(&x, (void *)0x06);
+	git_vector_insert(&x, (void *)0x07);
+	git_vector_insert(&x, (void *)0x08);
+	git_vector_insert(&x, (void *)0x09);
+	git_vector_insert(&x, (void *)0x0a);
+
+	git_vector_remove_range(&x, 0, 1);
+	assert_vector(&x, expected1, ARRAY_SIZE(expected1));
+
+	git_vector_remove_range(&x, 1, 1);
+	assert_vector(&x, expected2, ARRAY_SIZE(expected2));
+
+	git_vector_remove_range(&x, 4, 3);
+	assert_vector(&x, expected3, ARRAY_SIZE(expected3));
+
+	git_vector_remove_range(&x, 3, 2);
+	assert_vector(&x, expected4, ARRAY_SIZE(expected4));
+
+	git_vector_insert_null(&x, 0, 2);
+	assert_vector(&x, expected5, ARRAY_SIZE(expected5));
+
+	git_vector_insert_null(&x, 5, 1);
+	assert_vector(&x, expected6, ARRAY_SIZE(expected6));
+
+	git_vector_insert_null(&x, 4, 3);
+	assert_vector(&x, expected7, ARRAY_SIZE(expected7));
+
+	git_vector_remove_range(&x, 0, 3);
+	assert_vector(&x, expected8, ARRAY_SIZE(expected8));
+
+	git_vector_remove_range(&x, 1, 2);
+	assert_vector(&x, expected9, ARRAY_SIZE(expected9));
+
+	git_vector_remove_range(&x, 2, 2);
+	assert_vector(&x, expectedA, ARRAY_SIZE(expectedA));
+
+	git_vector_remove_range(&x, 1, 1);
+	assert_vector(&x, expectedB, ARRAY_SIZE(expectedB));
+
+	git_vector_remove_range(&x, 0, 1);
+	assert_vector(&x, NULL, 0);
+
+	git_vector_free(&x);
+}

tests/core/zstream.c

@@ -48,7 +48,7 @@ void test_core_zstream__basic(void)
 	char out[128];
 	size_t outlen = sizeof(out);
 
-	cl_git_pass(git_zstream_init(&z));
+	cl_git_pass(git_zstream_init(&z, GIT_ZSTREAM_DEFLATE));
 	cl_git_pass(git_zstream_set_input(&z, data, strlen(data) + 1));
 	cl_git_pass(git_zstream_get_output(out, &outlen, &z));
 	cl_assert(git_zstream_done(&z));
@@ -58,6 +58,25 @@ void test_core_zstream__basic(void)
 	assert_zlib_equal(data, strlen(data) + 1, out, outlen);
 }
 
+void test_core_zstream__fails_on_trailing_garbage(void)
+{
+	git_buf deflated = GIT_BUF_INIT, inflated = GIT_BUF_INIT;
+	size_t i = 0;
+
+	/* compress a simple string */
+	git_zstream_deflatebuf(&deflated, "foobar!!", 8);
+
+	/* append some garbage */
+	for (i = 0; i < 10; i++) {
+		git_buf_putc(&deflated, i);
+	}
+
+	cl_git_fail(git_zstream_inflatebuf(&inflated, deflated.ptr, deflated.size));
+
+	git_buf_free(&deflated);
+	git_buf_free(&inflated);
+}
+
 void test_core_zstream__buffer(void)
 {
 	git_buf out = GIT_BUF_INIT;
@@ -68,9 +87,10 @@ void test_core_zstream__buffer(void)
 
 #define BIG_STRING_PART "Big Data IS Big - Long Data IS Long - We need a buffer larger than 1024 x 1024 to make sure we trigger chunked compression - Big Big Data IS Bigger than Big - Long Long Data IS Longer than Long"
 
-static void compress_input_various_ways(git_buf *input)
+static void compress_and_decompress_input_various_ways(git_buf *input)
 {
 	git_buf out1 = GIT_BUF_INIT, out2 = GIT_BUF_INIT;
+	git_buf inflated = GIT_BUF_INIT;
 	size_t i, fixed_size = max(input->size / 2, 256);
 	char *fixed = git__malloc(fixed_size);
 	cl_assert(fixed);
@@ -93,7 +113,7 @@ static void compress_input_various_ways(git_buf *input)
 		}
 		cl_assert(use_fixed_size <= fixed_size);
 
-		cl_git_pass(git_zstream_init(&zs));
+		cl_git_pass(git_zstream_init(&zs, GIT_ZSTREAM_DEFLATE));
 		cl_git_pass(git_zstream_set_input(&zs, input->ptr, input->size));
 
 		while (!git_zstream_done(&zs)) {
@@ -112,7 +132,12 @@ static void compress_input_various_ways(git_buf *input)
 		git_buf_free(&out2);
 	}
 
+	cl_git_pass(git_zstream_inflatebuf(&inflated, out1.ptr, out1.size));
+	cl_assert_equal_i(input->size, inflated.size);
+	cl_assert(memcmp(input->ptr, inflated.ptr, inflated.size) == 0);
+
 	git_buf_free(&out1);
+	git_buf_free(&inflated);
 	git__free(fixed);
 }
 
@@ -129,14 +154,14 @@ void test_core_zstream__big_data(void)
 			cl_git_pass(
 				git_buf_put(&in, BIG_STRING_PART, strlen(BIG_STRING_PART)));
 
-		compress_input_various_ways(&in);
+		compress_and_decompress_input_various_ways(&in);
 
 		/* make a big string that's hard to compress */
 		srand(0xabad1dea);
 		for (scan = 0; scan < in.size; ++scan)
 			in.ptr[scan] = (char)rand();
 
-		compress_input_various_ways(&in);
+		compress_and_decompress_input_various_ways(&in);
 	}
 
 	git_buf_free(&in);

tests/diff/diff_helpers.c

@@ -241,3 +241,76 @@ void diff_print_raw(FILE *fp, git_diff *diff)
 		git_diff_print(diff, GIT_DIFF_FORMAT_RAW,
 			git_diff_print_callback__to_file_handle, fp ? fp : stderr));
 }
+
+static size_t num_modified_deltas(git_diff *diff)
+{
+	const git_diff_delta *delta;
+	size_t i, cnt = 0;
+
+	for (i = 0; i < git_diff_num_deltas(diff); i++) {
+		delta = git_diff_get_delta(diff, i);
+
+		if (delta->status != GIT_DELTA_UNMODIFIED)
+			cnt++;
+	}
+
+	return cnt;
+}
+
+void diff_assert_equal(git_diff *a, git_diff *b)
+{
+	const git_diff_delta *ad, *bd;
+	size_t i, j;
+
+	assert(a && b);
+
+	cl_assert_equal_i(num_modified_deltas(a), num_modified_deltas(b));
+
+	for (i = 0, j = 0;
+		i < git_diff_num_deltas(a) && j < git_diff_num_deltas(b); ) {
+
+		ad = git_diff_get_delta(a, i);
+		bd = git_diff_get_delta(b, j);
+
+		if (ad->status == GIT_DELTA_UNMODIFIED) {
+			i++;
+			continue;
+		}
+		if (bd->status == GIT_DELTA_UNMODIFIED) {
+			j++;
+			continue;
+		}
+
+		cl_assert_equal_i(ad->status, bd->status);
+		cl_assert_equal_i(ad->flags, bd->flags);
+		cl_assert_equal_i(ad->similarity, bd->similarity);
+		cl_assert_equal_i(ad->nfiles, bd->nfiles);
+
+		/* Don't examine the size or the flags of the deltas;
+		 * computed deltas have sizes (parsed deltas do not) and
+		 * computed deltas will have flags of `VALID_ID` and
+		 * `EXISTS` (parsed deltas will not query the ODB.)
+		 */
+
+		/* an empty id indicates that it wasn't presented, because
+		 * the diff was identical.  (eg, pure rename, mode change only, etc)
+		 */
+		if (ad->old_file.id_abbrev && bd->old_file.id_abbrev) {
+			cl_assert_equal_i(ad->old_file.id_abbrev, bd->old_file.id_abbrev);
+			cl_assert_equal_oid(&ad->old_file.id, &bd->old_file.id);
+			cl_assert_equal_i(ad->old_file.mode, bd->old_file.mode);
+		}
+		cl_assert_equal_s(ad->old_file.path, bd->old_file.path);
+
+		if (ad->new_file.id_abbrev && bd->new_file.id_abbrev) {
+			cl_assert_equal_oid(&ad->new_file.id, &bd->new_file.id);
+			cl_assert_equal_i(ad->new_file.id_abbrev, bd->new_file.id_abbrev);
+			cl_assert_equal_i(ad->new_file.mode, bd->new_file.mode);
+		}
+		cl_assert_equal_s(ad->new_file.path, bd->new_file.path);
+
+		i++;
+		j++;
+	}
+}
+

tests/diff/diff_helpers.h

@@ -68,3 +68,6 @@ extern int diff_foreach_via_iterator(
 
 extern void diff_print(FILE *fp, git_diff *diff);
 extern void diff_print_raw(FILE *fp, git_diff *diff);
+
+extern void diff_assert_equal(git_diff *a, git_diff *b);
+

tests/diff/format_email.c

@@ -4,6 +4,7 @@
 #include "buffer.h"
 #include "commit.h"
 #include "diff.h"
+#include "diff_generate.h"
 
 static git_repository *repo;
 
@@ -350,9 +351,6 @@ void test_diff_format_email__mode_change(void)
 	"diff --git a/file1.txt.renamed b/file1.txt.renamed\n" \
 	"old mode 100644\n" \
 	"new mode 100755\n" \
-	"index a97157a..a97157a\n" \
-	"--- a/file1.txt.renamed\n" \
-	"+++ b/file1.txt.renamed\n" \
 	"--\n" \
 	"libgit2 " LIBGIT2_VERSION "\n" \
 	"\n";

tests/diff/parse.c

+#include "clar_libgit2.h"
+#include "patch.h"
+#include "patch_parse.h"
+#include "diff_helpers.h"
+
+#include "../patch/patch_common.h"
+
+void test_diff_parse__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+void test_diff_parse__nonpatches_fail_with_notfound(void)
+{
+	git_diff *diff;
+	const char *not = PATCH_NOT_A_PATCH;
+	const char *not_with_leading = "Leading text.\n" PATCH_NOT_A_PATCH;
+	const char *not_with_trailing = PATCH_NOT_A_PATCH "Trailing text.\n";
+	const char *not_with_both = "Lead.\n" PATCH_NOT_A_PATCH "Trail.\n";
+
+	cl_git_fail_with(GIT_ENOTFOUND,
+		git_diff_from_buffer(&diff,
+		not,
+		strlen(not)));
+	cl_git_fail_with(GIT_ENOTFOUND,
+		git_diff_from_buffer(&diff,
+		not_with_leading,
+		strlen(not_with_leading)));
+	cl_git_fail_with(GIT_ENOTFOUND,
+		git_diff_from_buffer(&diff,
+		not_with_trailing,
+		strlen(not_with_trailing)));
+	cl_git_fail_with(GIT_ENOTFOUND,
+		git_diff_from_buffer(&diff,
+		not_with_both,
+		strlen(not_with_both)));
+}
+
+static void test_parse_invalid_diff(const char *invalid_diff)
+{
+	git_diff *diff;
+	git_buf buf = GIT_BUF_INIT;
+
+	/* throw some random (legitimate) diffs in with the given invalid
+	 * one.
+	 */
+	git_buf_puts(&buf, PATCH_ORIGINAL_TO_CHANGE_FIRSTLINE);
+	git_buf_puts(&buf, PATCH_BINARY_DELTA);
+	git_buf_puts(&buf, invalid_diff);
+	git_buf_puts(&buf, PATCH_ORIGINAL_TO_CHANGE_MIDDLE);
+	git_buf_puts(&buf, PATCH_BINARY_LITERAL);
+
+	cl_git_fail_with(GIT_ERROR,
+		git_diff_from_buffer(&diff, buf.ptr, buf.size));
+
+	git_buf_free(&buf);
+}
+
+void test_diff_parse__invalid_patches_fails(void)
+{
+	test_parse_invalid_diff(PATCH_CORRUPT_MISSING_NEW_FILE);
+	test_parse_invalid_diff(PATCH_CORRUPT_MISSING_OLD_FILE);
+	test_parse_invalid_diff(PATCH_CORRUPT_NO_CHANGES);
+	test_parse_invalid_diff(PATCH_CORRUPT_MISSING_HUNK_HEADER);
+}
+
+static void test_tree_to_tree_computed_to_parsed(
+	const char *sandbox, const char *a_id, const char *b_id,
+	uint32_t diff_flags, uint32_t find_flags)
+{
+	git_repository *repo;
+	git_diff *computed, *parsed;
+	git_tree *a, *b;
+	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
+	git_diff_find_options findopts = GIT_DIFF_FIND_OPTIONS_INIT;
+	git_buf computed_buf = GIT_BUF_INIT;
+
+	repo = cl_git_sandbox_init(sandbox);
+
+	opts.id_abbrev = GIT_OID_HEXSZ;
+	opts.flags = GIT_DIFF_SHOW_BINARY | diff_flags;
+	findopts.flags = find_flags;
+
+	cl_assert((a = resolve_commit_oid_to_tree(repo, a_id)) != NULL);
+	cl_assert((b = resolve_commit_oid_to_tree(repo, b_id)) != NULL);
+
+	cl_git_pass(git_diff_tree_to_tree(&computed, repo, a, b, &opts));
+
+	if (find_flags)
+		cl_git_pass(git_diff_find_similar(computed, &findopts));
+
+	cl_git_pass(git_diff_to_buf(&computed_buf,
+		computed, GIT_DIFF_FORMAT_PATCH));
+
+	cl_git_pass(git_diff_from_buffer(&parsed,
+		computed_buf.ptr, computed_buf.size));
+
+	diff_assert_equal(computed, parsed);
+
+	git_tree_free(a);
+	git_tree_free(b);
+
+	git_diff_free(computed);
+	git_diff_free(parsed);
+
+	git_buf_free(&computed_buf);
+
+	cl_git_sandbox_cleanup();
+}
+
+void test_diff_parse__can_parse_generated_diff(void)
+{
+	test_tree_to_tree_computed_to_parsed(
+		"diff", "d70d245e", "7a9e0b02", 0, 0);
+	test_tree_to_tree_computed_to_parsed(
+		"unsymlinked.git", "806999", "a8595c", 0, 0);
+	test_tree_to_tree_computed_to_parsed("diff",
+		"d70d245ed97ed2aa596dd1af6536e4bfdb047b69",
+		"7a9e0b02e63179929fed24f0a3e0f19168114d10", 0, 0);
+	test_tree_to_tree_computed_to_parsed(
+		"unsymlinked.git", "7fccd7", "806999", 0, 0);
+	test_tree_to_tree_computed_to_parsed(
+		"unsymlinked.git", "7fccd7", "a8595c", 0, 0);
+	test_tree_to_tree_computed_to_parsed(
+		"attr", "605812a", "370fe9ec22", 0, 0);
+	test_tree_to_tree_computed_to_parsed(
+		"attr", "f5b0af1fb4f5c", "370fe9ec22", 0, 0);
+	test_tree_to_tree_computed_to_parsed(
+		"diff", "d70d245e", "d70d245e", 0, 0);
+	test_tree_to_tree_computed_to_parsed("diff_format_email",
+		"873806f6f27e631eb0b23e4b56bea2bfac14a373",
+		"897d3af16ca9e420cd071b1c4541bd2b91d04c8c",
+		GIT_DIFF_SHOW_BINARY, 0);
+	test_tree_to_tree_computed_to_parsed("diff_format_email",
+		"897d3af16ca9e420cd071b1c4541bd2b91d04c8c",
+		"873806f6f27e631eb0b23e4b56bea2bfac14a373",
+		GIT_DIFF_SHOW_BINARY, 0);
+	test_tree_to_tree_computed_to_parsed("renames",
+		"31e47d8c1fa36d7f8d537b96158e3f024de0a9f2",
+		"2bc7f351d20b53f1c72c16c4b036e491c478c49a",
+		0, GIT_DIFF_FIND_RENAMES);
+	test_tree_to_tree_computed_to_parsed("renames",
+		"31e47d8c1fa36d7f8d537b96158e3f024de0a9f2",
+		"2bc7f351d20b53f1c72c16c4b036e491c478c49a",
+		GIT_DIFF_INCLUDE_UNMODIFIED,
+		0);
+	test_tree_to_tree_computed_to_parsed("renames",
+		"31e47d8c1fa36d7f8d537b96158e3f024de0a9f2",
+		"2bc7f351d20b53f1c72c16c4b036e491c478c49a",
+		GIT_DIFF_INCLUDE_UNMODIFIED,
+		GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED | GIT_DIFF_FIND_EXACT_MATCH_ONLY);
+}
+

tests/diff/rename.c

@@ -1702,3 +1702,49 @@ void test_diff_rename__blank_files_not_renamed_when_not_ignoring_whitespace(void
 	expect_files_not_renamed("", "\n\n\n\n",  GIT_DIFF_FIND_DONT_IGNORE_WHITESPACE);
 	expect_files_not_renamed("\n\n\n\n", "\r\n\r\n\r\n",  GIT_DIFF_FIND_DONT_IGNORE_WHITESPACE);
 }
+
+/* test that 100% renames and copies emit the correct patch file
+ * git diff --find-copies-harder -M100 -B100 \
+ *          31e47d8c1fa36d7f8d537b96158e3f024de0a9f2 \
+ *          2bc7f351d20b53f1c72c16c4b036e491c478c49a
+ */
+void test_diff_rename__identical(void)
+{
+	const char *old_sha = "31e47d8c1fa36d7f8d537b96158e3f024de0a9f2";
+	const char *new_sha = "2bc7f351d20b53f1c72c16c4b036e491c478c49a";
+	git_tree *old_tree, *new_tree;
+    git_diff *diff;
+	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
+	git_diff_find_options find_opts = GIT_DIFF_FIND_OPTIONS_INIT;
+	git_buf diff_buf = GIT_BUF_INIT;
+	const char *expected =
+		"diff --git a/serving.txt b/sixserving.txt\n"
+		"similarity index 100%\n"
+		"rename from serving.txt\n"
+		"rename to sixserving.txt\n"
+		"diff --git a/sevencities.txt b/songofseven.txt\n"
+		"similarity index 100%\n"
+		"copy from sevencities.txt\n"
+		"copy to songofseven.txt\n";
+
+	old_tree = resolve_commit_oid_to_tree(g_repo, old_sha);
+	new_tree = resolve_commit_oid_to_tree(g_repo, new_sha);
+
+	diff_opts.flags |= GIT_DIFF_INCLUDE_UNMODIFIED;
+	find_opts.flags = GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED |
+		GIT_DIFF_FIND_EXACT_MATCH_ONLY;
+
+	cl_git_pass(git_diff_tree_to_tree(&diff,
+		g_repo, old_tree, new_tree, &diff_opts));
+	cl_git_pass(git_diff_find_similar(diff, &find_opts));
+
+	cl_git_pass(git_diff_to_buf(&diff_buf, diff, GIT_DIFF_FORMAT_PATCH));
+
+	cl_assert_equal_s(expected, diff_buf.ptr);
+
+	git_buf_free(&diff_buf);
+	git_diff_free(diff);
+	git_tree_free(old_tree);
+	git_tree_free(new_tree);
+}
+

tests/diff/stats.c

@@ -4,6 +4,7 @@
 #include "buffer.h"
 #include "commit.h"
 #include "diff.h"
+#include "diff_generate.h"
 
 static git_repository *_repo;
 static git_diff_stats *_stats;

tests/merge/trees/treediff.c

@@ -3,6 +3,7 @@
 #include "merge.h"
 #include "../merge_helpers.h"
 #include "diff.h"
+#include "diff_tform.h"
 #include "git2/sys/hashsig.h"
 
 static git_repository *repo;

tests/patch/parse.c

+#include "clar_libgit2.h"
+#include "patch.h"
+#include "patch_parse.h"
+
+#include "patch_common.h"
+
+static void ensure_patch_validity(git_patch *patch)
+{
+	const git_diff_delta *delta;
+	char idstr[GIT_OID_HEXSZ+1] = {0};
+
+	cl_assert((delta = git_patch_get_delta(patch)) != NULL);
+	cl_assert_equal_i(2, delta->nfiles);
+
+	cl_assert_equal_s(delta->old_file.path, "file.txt");
+	cl_assert(delta->old_file.mode == GIT_FILEMODE_BLOB);
+	cl_assert_equal_i(7, delta->old_file.id_abbrev);
+	git_oid_nfmt(idstr, delta->old_file.id_abbrev, &delta->old_file.id);
+	cl_assert_equal_s(idstr, "9432026");
+	cl_assert_equal_i(0, delta->old_file.size);
+
+	cl_assert_equal_s(delta->new_file.path, "file.txt");
+	cl_assert(delta->new_file.mode == GIT_FILEMODE_BLOB);
+	cl_assert_equal_i(7, delta->new_file.id_abbrev);
+	git_oid_nfmt(idstr, delta->new_file.id_abbrev, &delta->new_file.id);
+	cl_assert_equal_s(idstr, "cd8fd12");
+	cl_assert_equal_i(0, delta->new_file.size);
+}
+
+void test_patch_parse__original_to_change_middle(void)
+{
+	git_patch *patch;
+
+	cl_git_pass(git_patch_from_buffer(
+		&patch, PATCH_ORIGINAL_TO_CHANGE_MIDDLE,
+		strlen(PATCH_ORIGINAL_TO_CHANGE_MIDDLE), NULL));
+	ensure_patch_validity(patch);
+	git_patch_free(patch);
+}
+
+void test_patch_parse__leading_and_trailing_garbage(void)
+{
+	git_patch *patch;
+	const char *leading = "This is some leading garbage.\n"
+		"Maybe it's email headers?\n"
+		"\n"
+		PATCH_ORIGINAL_TO_CHANGE_MIDDLE;
+	const char *trailing = PATCH_ORIGINAL_TO_CHANGE_MIDDLE
+		"\n"
+		"This is some trailing garbage.\n"
+		"Maybe it's an email signature?\n";
+	const char *both = "Here's some leading garbage\n"
+		PATCH_ORIGINAL_TO_CHANGE_MIDDLE
+		"And here's some trailing.\n";
+
+	cl_git_pass(git_patch_from_buffer(&patch, leading, strlen(leading),
+		NULL));
+	ensure_patch_validity(patch);
+	git_patch_free(patch);
+
+	cl_git_pass(git_patch_from_buffer(&patch, trailing, strlen(trailing),
+		NULL));
+	ensure_patch_validity(patch);
+	git_patch_free(patch);
+
+	cl_git_pass(git_patch_from_buffer(&patch, both, strlen(both),
+		NULL));
+	ensure_patch_validity(patch);
+	git_patch_free(patch);
+}
+
+void test_patch_parse__nonpatches_fail_with_notfound(void)
+{
+	git_patch *patch;
+
+	cl_git_fail_with(GIT_ENOTFOUND,
+		git_patch_from_buffer(&patch, PATCH_NOT_A_PATCH,
+		strlen(PATCH_NOT_A_PATCH), NULL));
+}
+
+void test_patch_parse__invalid_patches_fails(void)
+{
+	git_patch *patch;
+
+	cl_git_fail_with(GIT_ERROR,
+		git_patch_from_buffer(&patch, PATCH_CORRUPT_GIT_HEADER,
+		strlen(PATCH_CORRUPT_GIT_HEADER), NULL));
+	cl_git_fail_with(GIT_ERROR,
+		git_patch_from_buffer(&patch,
+		PATCH_CORRUPT_MISSING_NEW_FILE,
+		strlen(PATCH_CORRUPT_MISSING_NEW_FILE), NULL));
+	cl_git_fail_with(GIT_ERROR,
+		git_patch_from_buffer(&patch,
+		PATCH_CORRUPT_MISSING_OLD_FILE,
+		strlen(PATCH_CORRUPT_MISSING_OLD_FILE), NULL));
+	cl_git_fail_with(GIT_ERROR,
+		git_patch_from_buffer(&patch, PATCH_CORRUPT_NO_CHANGES,
+		strlen(PATCH_CORRUPT_NO_CHANGES), NULL));
+	cl_git_fail_with(GIT_ERROR,
+		git_patch_from_buffer(&patch,
+		PATCH_CORRUPT_MISSING_HUNK_HEADER,
+		strlen(PATCH_CORRUPT_MISSING_HUNK_HEADER), NULL));
+}
+

tests/patch/print.c

+#include "clar_libgit2.h"
+#include "patch.h"
+#include "patch_parse.h"
+
+#include "patch_common.h"
+
+
+/* sanity check the round-trip of patch parsing:  ensure that we can parse
+ * and then print a variety of patch files.
+ */
+
+void patch_print_from_patchfile(const char *data, size_t len)
+{
+	git_patch *patch;
+	git_buf buf = GIT_BUF_INIT;
+
+	cl_git_pass(git_patch_from_buffer(&patch, data, len, NULL));
+	cl_git_pass(git_patch_to_buf(&buf, patch));
+
+	cl_assert_equal_s(data, buf.ptr);
+
+	git_patch_free(patch);
+	git_buf_free(&buf);
+}
+
+void test_patch_print__change_middle(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_CHANGE_MIDDLE,
+		strlen(PATCH_ORIGINAL_TO_CHANGE_MIDDLE));
+}
+
+void test_patch_print__change_middle_nocontext(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_CHANGE_MIDDLE_NOCONTEXT,
+		strlen(PATCH_ORIGINAL_TO_CHANGE_MIDDLE_NOCONTEXT));
+}
+
+void test_patch_print__change_firstline(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_CHANGE_FIRSTLINE,
+		strlen(PATCH_ORIGINAL_TO_CHANGE_FIRSTLINE));
+}
+
+void test_patch_print__change_lastline(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_CHANGE_LASTLINE,
+		strlen(PATCH_ORIGINAL_TO_CHANGE_LASTLINE));
+}
+
+void test_patch_print__prepend(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_PREPEND,
+		strlen(PATCH_ORIGINAL_TO_PREPEND));
+}
+
+void test_patch_print__prepend_nocontext(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_PREPEND_NOCONTEXT,
+		strlen(PATCH_ORIGINAL_TO_PREPEND_NOCONTEXT));
+}
+
+void test_patch_print__append(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_APPEND,
+		strlen(PATCH_ORIGINAL_TO_APPEND));
+}
+
+void test_patch_print__append_nocontext(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_APPEND_NOCONTEXT,
+		strlen(PATCH_ORIGINAL_TO_APPEND_NOCONTEXT));
+}
+
+void test_patch_print__prepend_and_append(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_PREPEND_AND_APPEND,
+		strlen(PATCH_ORIGINAL_TO_PREPEND_AND_APPEND));
+}
+
+void test_patch_print__to_empty_file(void)
+{
+	patch_print_from_patchfile(PATCH_ORIGINAL_TO_EMPTY_FILE,
+		strlen(PATCH_ORIGINAL_TO_EMPTY_FILE));
+}
+
+void test_patch_print__from_empty_file(void)
+{
+	patch_print_from_patchfile(PATCH_EMPTY_FILE_TO_ORIGINAL,
+		strlen(PATCH_EMPTY_FILE_TO_ORIGINAL));
+}
+
+void test_patch_print__add(void)
+{
+	patch_print_from_patchfile(PATCH_ADD_ORIGINAL,
+		strlen(PATCH_ADD_ORIGINAL));
+}
+
+void test_patch_print__delete(void)
+{
+	patch_print_from_patchfile(PATCH_DELETE_ORIGINAL,
+		strlen(PATCH_DELETE_ORIGINAL));
+}
+
+void test_patch_print__rename_exact(void)
+{
+	patch_print_from_patchfile(PATCH_RENAME_EXACT,
+		strlen(PATCH_RENAME_EXACT));
+}
+
+void test_patch_print__rename_similar(void)
+{
+	patch_print_from_patchfile(PATCH_RENAME_SIMILAR,
+		strlen(PATCH_RENAME_SIMILAR));
+}
+
+void test_patch_print__rename_exact_quotedname(void)
+{
+	patch_print_from_patchfile(PATCH_RENAME_EXACT_QUOTEDNAME,
+		strlen(PATCH_RENAME_EXACT_QUOTEDNAME));
+}
+
+void test_patch_print__rename_similar_quotedname(void)
+{
+	patch_print_from_patchfile(PATCH_RENAME_SIMILAR_QUOTEDNAME,
+		strlen(PATCH_RENAME_SIMILAR_QUOTEDNAME));
+}
+
+void test_patch_print__modechange_unchanged(void)
+{
+	patch_print_from_patchfile(PATCH_MODECHANGE_UNCHANGED,
+		strlen(PATCH_MODECHANGE_UNCHANGED));
+}
+
+void test_patch_print__modechange_modified(void)
+{
+	patch_print_from_patchfile(PATCH_MODECHANGE_MODIFIED,
+		strlen(PATCH_MODECHANGE_MODIFIED));
+}
+
+void test_patch_print__binary_literal(void)
+{
+	patch_print_from_patchfile(PATCH_BINARY_LITERAL,
+		strlen(PATCH_BINARY_LITERAL));
+}
+
+void test_patch_print__binary_delta(void)
+{
+	patch_print_from_patchfile(PATCH_BINARY_DELTA,
+		strlen(PATCH_BINARY_DELTA));
+}
+
+void test_patch_print__binary_add(void)
+{
+	patch_print_from_patchfile(PATCH_BINARY_ADD,
+		strlen(PATCH_BINARY_ADD));
+}
+
+void test_patch_print__binary_delete(void)
+{
+	patch_print_from_patchfile(PATCH_BINARY_DELETE,
+		strlen(PATCH_BINARY_DELETE));
+}
+
+void test_patch_print__not_reversible(void)
+{
+	patch_print_from_patchfile(PATCH_BINARY_NOT_REVERSIBLE,
+		strlen(PATCH_BINARY_NOT_REVERSIBLE));
+}