Minor fixes, cleanups, and clarifications

There are three actual changes in this commit:

1. When the trailing newline of a file is removed in a diff, the
   change will now be reported with `GIT_DIFF_LINE_DEL_EOFNL` passed
   to the callback.  Previously, the `ADD_EOFNL` constant was given
   which was just an error in my understanding of when the various
   circumstances arose.  `GIT_DIFF_LINE_ADD_EOFNL` is deprecated and
   should never be generated.  A new newline is simply an `ADD`.
2. Rewrote the `diff_delta__merge_like_cgit` function that contains
   the core logic of the `git_diff_merge` implementation.  The new
   version doesn't actually have significantly different behavior,
   but the logic should be much more obvious, I think.
3. Fixed a bug in `git_diff_merge` where it freed a string pool
   while some of the string data was still in use.  This led to
   `git_diff_print_patch` accessing memory that had been freed.

The rest of this commit contains improved documentation in `diff.h`
to make the behavior and the equivalencies with core git clearer,
and a bunch of new tests to cover the various cases, oh and a minor
simplification of `examples/diff.c`.

examples/diff.c

@@ -185,9 +185,7 @@ int main(int argc, char *argv[])
 
 	/* open repo */
 
-	check(git_repository_discover(path, sizeof(path), dir, 0, "/"),
-		"Could not discover repository");
-	check(git_repository_open(&repo, path),
+	check(git_repository_open_ext(&repo, dir, 0, NULL),
 		"Could not open repository");
 
 	if (treeish1)

include/git2/diff.h

@@ -29,6 +29,10 @@
  */
 GIT_BEGIN_DECL
 
+/**
+ * Flags for diff options.  A combination of these flags can be passed
+ * in via the `flags` value in the `git_diff_options`.
+ */
 enum {
 	GIT_DIFF_NORMAL = 0,
 	GIT_DIFF_REVERSE = (1 << 0),
@@ -160,15 +164,16 @@ typedef int (*git_diff_hunk_fn)(
  * the file or hunk headers.
  */
 enum {
-	/* these values will be sent to `git_diff_data_fn` along with the line */
+	/* These values will be sent to `git_diff_data_fn` along with the line */
 	GIT_DIFF_LINE_CONTEXT   = ' ',
 	GIT_DIFF_LINE_ADDITION  = '+',
 	GIT_DIFF_LINE_DELETION  = '-',
-	GIT_DIFF_LINE_ADD_EOFNL = '\n', /**< LF was added at end of file */
+	GIT_DIFF_LINE_ADD_EOFNL = '\n', /**< DEPRECATED */
 	GIT_DIFF_LINE_DEL_EOFNL = '\0', /**< LF was removed at end of file */
-	/* these values will only be sent to a `git_diff_data_fn` when the content
-	 * of a diff is being formatted (eg. through git_diff_print_patch() or
-	 * git_diff_print_compact(), for instance).
+
+	/* The following values will only be sent to a `git_diff_data_fn` when
+	 * the content of a diff is being formatted (eg. through
+	 * git_diff_print_patch() or git_diff_print_compact(), for instance).
 	 */
 	GIT_DIFF_LINE_FILE_HDR  = 'F',
 	GIT_DIFF_LINE_HUNK_HDR  = 'H',
@@ -206,6 +211,8 @@ GIT_EXTERN(void) git_diff_list_free(git_diff_list *diff);
 /**
  * Compute a difference between two tree objects.
  *
+ * This is equivalent to `git diff <treeish> <treeish>`
+ *
  * @param repo The repository containing the trees.
  * @param opts Structure with options to influence diff or NULL for defaults.
  * @param old_tree A git_tree object to diff from.
@@ -222,6 +229,9 @@ GIT_EXTERN(int) git_diff_tree_to_tree(
 /**
  * Compute a difference between a tree and the index.
  *
+ * This is equivalent to `git diff --cached <treeish>` or if you pass
+ * the HEAD tree, then like `git diff --cached`.
+ *
  * @param repo The repository containing the tree and index.
  * @param opts Structure with options to influence diff or NULL for defaults.
  * @param old_tree A git_tree object to diff from.
@@ -236,6 +246,11 @@ GIT_EXTERN(int) git_diff_index_to_tree(
 /**
  * Compute a difference between the working directory and the index.
  *
+ * This matches the `git diff` command.  See the note below on
+ * `git_diff_workdir_to_tree` for a discussion of the difference between
+ * `git diff` and `git diff HEAD` and how to emulate a `git diff <treeish>`
+ * using libgit2.
+ *
  * @param repo The repository.
  * @param opts Structure with options to influence diff or NULL for defaults.
  * @param diff A pointer to a git_diff_list pointer that will be allocated.
@@ -248,14 +263,24 @@ GIT_EXTERN(int) git_diff_workdir_to_index(
 /**
  * Compute a difference between the working directory and a tree.
  *
- * This returns strictly the differences between the tree and the
- * files contained in the working directory, regardless of the state
- * of files in the index.  There is no direct equivalent in C git.
+ * This is *NOT* the same as `git diff <treeish>`.  Running `git diff HEAD`
+ * or the like actually uses information from the index, along with the tree
+ * and workdir dir info.
  *
- * This is *NOT* the same as 'git diff HEAD' or 'git diff <SHA>'.  Those
- * commands diff the tree, the index, and the workdir.  To emulate those
- * functions, call `git_diff_index_to_tree` and `git_diff_workdir_to_index`,
- * then call `git_diff_merge` on the results.
+ * This function returns strictly the differences between the tree and the
+ * files contained in the working directory, regardless of the state of
+ * files in the index.  It may come as a surprise, but there is no direct
+ * equivalent in core git.
+ *
+ * To emulate `git diff <treeish>`, you should call both
+ * `git_diff_index_to_tree` and `git_diff_workdir_to_index`, then call
+ * `git_diff_merge` on the results.  That will yield a `git_diff_list` that
+ * matches the git output.
+ *
+ * If this seems confusing, take the case of a file with a staged deletion
+ * where the file has then been put back into the working dir and modified.
+ * The tree-to-workdir diff for that file is 'modified', but core git would
+ * show status 'deleted' since there is a pending deletion in the index.
  *
  * @param repo The repository containing the tree.
  * @param opts Structure with options to influence diff or NULL for defaults.
@@ -298,10 +323,23 @@ GIT_EXTERN(int) git_diff_merge(
 /**
  * Iterate over a diff list issuing callbacks.
  *
- * If the hunk and/or line callbacks are not NULL, then this will calculate
- * text diffs for all files it thinks are not binary.  If those are both
- * NULL, then this will not bother with the text diffs, so it can be
- * efficient.
+ * This will iterate through all of the files described in a diff.  You
+ * should provide a file callback to learn about each file.
+ *
+ * The "hunk" and "line" callbacks are optional, and the text diff of the
+ * files will only be calculated if they are not NULL.  Of course, these
+ * callbacks will not be invoked for binary files on the diff list or for
+ * files whose only changed is a file mode change.
+ *
+ * @param diff A git_diff_list generated by one of the above functions.
+ * @param cb_data Reference pointer that will be passed to your callbacks.
+ * @param file_cb Callback function to make per file in the diff.
+ * @param hunk_cb Optional callback to make per hunk of text diff.  This
+ *                callback is called to describe a range of lines in the
+ *                diff.  It will not be issued for binary files.
+ * @param line_cb Optional callback to make per line of diff text.  This
+ *                same callback will be made for context lines, added, and
+ *                removed lines, and even for a deleted trailing newline.
  */
 GIT_EXTERN(int) git_diff_foreach(
 	git_diff_list *diff,
@@ -322,6 +360,14 @@ GIT_EXTERN(int) git_diff_print_compact(
  * Iterate over a diff generating text output like "git diff".
  *
  * This is a super easy way to generate a patch from a diff.
+ *
+ * @param diff A git_diff_list generated by one of the above functions.
+ * @param cb_data Reference pointer that will be passed to your callbacks.
+ * @param print_cb Callback function to output lines of the diff.  This
+ *                 same function will be called for file headers, hunk
+ *                 headers, and diff lines.  Fortunately, you can probably
+ *                 use various GIT_DIFF_LINE constants to determine what
+ *                 text you are given.
  */
 GIT_EXTERN(int) git_diff_print_patch(
 	git_diff_list *diff,
@@ -338,13 +384,14 @@ GIT_EXTERN(int) git_diff_print_patch(
 /**
  * Directly run a text diff on two blobs.
  *
- * Compared to a file, a blob lacks some contextual information. As such, the
- * `git_diff_file` parameters of the callbacks will be filled accordingly to the following:
- * `mode` will be set to 0, `path` will be set to NULL. When dealing with a NULL blob, `oid`
- * will be set to 0.
+ * Compared to a file, a blob lacks some contextual information. As such,
+ * the `git_diff_file` parameters of the callbacks will be filled
+ * accordingly to the following: `mode` will be set to 0, `path` will be set
+ * to NULL. When dealing with a NULL blob, `oid` will be set to 0.
  *
- * When at least one of the blobs being dealt with is binary, the `git_diff_delta` binary
- * attribute will be set to 1 and no call to the hunk_cb nor line_cb will be made.
+ * When at least one of the blobs being dealt with is binary, the
+ * `git_diff_delta` binary attribute will be set to 1 and no call to the
+ * hunk_cb nor line_cb will be made.
  */
 GIT_EXTERN(int) git_diff_blobs(
 	git_blob *old_blob,

src/diff.c

@@ -130,37 +130,50 @@ fail:
 static git_diff_delta *diff_delta__merge_like_cgit(
 	const git_diff_delta *a, const git_diff_delta *b, git_pool *pool)
 {
-	git_diff_delta *dup = diff_delta__dup(a, pool);
-	if (!dup)
-		return NULL;
-
-	if (git_oid_cmp(&dup->new_file.oid, &b->new_file.oid) == 0)
-		return dup;
-
-	git_oid_cpy(&dup->new_file.oid, &b->new_file.oid);
-
-	dup->new_file.mode = b->new_file.mode;
-	dup->new_file.size = b->new_file.size;
-	dup->new_file.flags = b->new_file.flags;
+	git_diff_delta *dup;
 
 	/* Emulate C git for merging two diffs (a la 'git diff <sha>').
 	 *
 	 * When C git does a diff between the work dir and a tree, it actually
 	 * diffs with the index but uses the workdir contents.  This emulates
 	 * those choices so we can emulate the type of diff.
+	 *
+	 * We have three file descriptions here, let's call them:
+	 *  f1 = a->old_file
+	 *  f2 = a->new_file AND b->old_file
+	 *  f3 = b->new_file
 	 */
-	if (git_oid_cmp(&dup->old_file.oid, &dup->new_file.oid) == 0) {
-		if (dup->status == GIT_DELTA_DELETED)
-			/* preserve pending delete info */;
-		else if (b->status == GIT_DELTA_UNTRACKED ||
-				 b->status == GIT_DELTA_IGNORED)
-			dup->status = b->status;
-		else
+
+	/* if f2 == f3 or f2 is deleted, then just dup the 'a' diff */
+	if (b->status == GIT_DELTA_UNMODIFIED || a->status == GIT_DELTA_DELETED)
+		return diff_delta__dup(a, pool);
+
+	/* otherwise, base this diff on the 'b' diff */
+	if ((dup = diff_delta__dup(b, pool)) == NULL)
+		return NULL;
+
+	/* If 'a' status is uninteresting, then we're done */
+	if (a->status == GIT_DELTA_UNMODIFIED)
+		return dup;
+
+	assert(a->status != GIT_DELTA_UNMODIFIED);
+	assert(b->status != GIT_DELTA_UNMODIFIED);
+
+	/* A cgit exception is that the diff of a file that is only in the
+	 * index (i.e. not in HEAD nor workdir) is given as empty.
+	 */
+	if (dup->status == GIT_DELTA_DELETED) {
+		if (a->status == GIT_DELTA_ADDED)
 			dup->status = GIT_DELTA_UNMODIFIED;
+		/* else don't overwrite DELETE status */
+	} else {
+		dup->status = a->status;
 	}
-	else if (dup->status == GIT_DELTA_UNMODIFIED ||
-			 b->status == GIT_DELTA_DELETED)
-		dup->status = b->status;
+
+	git_oid_cpy(&dup->old_file.oid, &a->old_file.oid);
+	dup->old_file.mode  = a->old_file.mode;
+	dup->old_file.size  = a->old_file.size;
+	dup->old_file.flags = a->old_file.flags;
 
 	return dup;
 }
@@ -783,6 +796,12 @@ int git_diff_merge(
 		git_vector_swap(&onto->deltas, &onto_new);
 		git_pool_swap(&onto->pool, &onto_pool);
 		onto->new_src = from->new_src;
+
+		/* prefix strings also come from old pool, so recreate those.*/
+		onto->opts.old_prefix =
+			git_pool_strdup(&onto->pool, onto->opts.old_prefix);
+		onto->opts.new_prefix =
+			git_pool_strdup(&onto->pool, onto->opts.new_prefix);
 	}
 
 	git_vector_foreach(&onto_new, i, delta)

src/diff_output.c

@@ -83,12 +83,13 @@ static int diff_output_cb(void *priv, mmbuffer_t *bufs, int len)
 			info->cb_data, info->delta, &info->range, origin, bufs[1].ptr, bufs[1].size) < 0)
 			return -1;
 
-		/* deal with adding and removing newline at EOF */
+		/* This should only happen if we are adding a line that does not
+		 * have a newline at the end and the old code did.  In that case,
+		 * we have a ADD with a DEL_EOFNL as a pair.
+		 */
 		if (len == 3) {
-			if (origin == GIT_DIFF_LINE_ADDITION)
-				origin = GIT_DIFF_LINE_ADD_EOFNL;
-			else
-				origin = GIT_DIFF_LINE_DEL_EOFNL;
+			origin = (origin == GIT_DIFF_LINE_ADDITION) ?
+				GIT_DIFF_LINE_DEL_EOFNL : GIT_DIFF_LINE_ADD_EOFNL;
 
 			return info->line_cb(
 				info->cb_data, info->delta, &info->range, origin, bufs[2].ptr, bufs[2].size);

tests-clar/diff/diff_helpers.c

@@ -85,11 +85,16 @@ int diff_line_fn(
 		e->line_ctxt++;
 		break;
 	case GIT_DIFF_LINE_ADDITION:
-	case GIT_DIFF_LINE_ADD_EOFNL:
 		e->line_adds++;
 		break;
+	case GIT_DIFF_LINE_ADD_EOFNL:
+		assert(0);
+		break;
 	case GIT_DIFF_LINE_DELETION:
+		e->line_dels++;
+		break;
 	case GIT_DIFF_LINE_DEL_EOFNL:
+		/* technically not a line delete, but we'll count it as such */
 		e->line_dels++;
 		break;
 	default:

tests-clar/diff/tree.c

@@ -116,7 +116,7 @@ void test_diff_tree__options(void)
 		{ 5, 3, 0, 2, 0, 0, 0, 4, 0, 0, 51, 2, 46, 3 },
 		{ 5, 3, 0, 2, 0, 0, 0, 4, 0, 0, 53, 4, 46, 3 },
 		{ 5, 0, 3, 2, 0, 0, 0, 4, 0, 0, 52, 3, 3, 46 },
-		{ 5, 3, 0, 2, 0, 0, 0, 5, 0, 0, 54, 3, 48, 3 },
+		{ 5, 3, 0, 2, 0, 0, 0, 5, 0, 0, 54, 3, 47, 4 },
 		/* c vs d tests */
 		{ 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 22, 9, 10, 3 },
 		{ 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 19, 12, 7, 0 },

tests-clar/diff/workdir.c

@@ -92,12 +92,12 @@ void test_diff_workdir__to_tree(void)
 	cl_git_pass(git_diff_foreach(
 		diff, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(exp.files == 14);
-	cl_assert(exp.file_adds == 0);
-	cl_assert(exp.file_dels == 4);
-	cl_assert(exp.file_mods == 4);
-	cl_assert(exp.file_ignored == 1);
-	cl_assert(exp.file_untracked == 5);
+	cl_assert_equal_i(14, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(4, exp.file_dels);
+	cl_assert_equal_i(4, exp.file_mods);
+	cl_assert_equal_i(1, exp.file_ignored);
+	cl_assert_equal_i(5, exp.file_untracked);
 
 	/* Since there is no git diff equivalent, let's just assume that the
 	 * text diffs produced by git_diff_foreach are accurate here.  We will
@@ -120,19 +120,19 @@ void test_diff_workdir__to_tree(void)
 	cl_git_pass(git_diff_foreach(
 		diff, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(exp.files == 15);
-	cl_assert(exp.file_adds == 2);
-	cl_assert(exp.file_dels == 5);
-	cl_assert(exp.file_mods == 4);
-	cl_assert(exp.file_ignored == 1);
-	cl_assert(exp.file_untracked == 3);
+	cl_assert_equal_i(15, exp.files);
+	cl_assert_equal_i(2, exp.file_adds);
+	cl_assert_equal_i(5, exp.file_dels);
+	cl_assert_equal_i(4, exp.file_mods);
+	cl_assert_equal_i(1, exp.file_ignored);
+	cl_assert_equal_i(3, exp.file_untracked);
 
-	cl_assert(exp.hunks == 11);
+	cl_assert_equal_i(11, exp.hunks);
 
-	cl_assert(exp.lines == 17);
-	cl_assert(exp.line_ctxt == 4);
-	cl_assert(exp.line_adds == 8);
-	cl_assert(exp.line_dels == 5);
+	cl_assert_equal_i(17, exp.lines);
+	cl_assert_equal_i(4, exp.line_ctxt);
+	cl_assert_equal_i(8, exp.line_adds);
+	cl_assert_equal_i(5, exp.line_dels);
 
 	git_diff_list_free(diff);
 	diff = NULL;
@@ -149,19 +149,19 @@ void test_diff_workdir__to_tree(void)
 	cl_git_pass(git_diff_foreach(
 		diff, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
 
-	cl_assert(exp.files == 16);
-	cl_assert(exp.file_adds == 5);
-	cl_assert(exp.file_dels == 4);
-	cl_assert(exp.file_mods == 3);
-	cl_assert(exp.file_ignored == 1);
-	cl_assert(exp.file_untracked == 3);
+	cl_assert_equal_i(16, exp.files);
+	cl_assert_equal_i(5, exp.file_adds);
+	cl_assert_equal_i(4, exp.file_dels);
+	cl_assert_equal_i(3, exp.file_mods);
+	cl_assert_equal_i(1, exp.file_ignored);
+	cl_assert_equal_i(3, exp.file_untracked);
 
-	cl_assert(exp.hunks == 12);
+	cl_assert_equal_i(12, exp.hunks);
 
-	cl_assert(exp.lines == 19);
-	cl_assert(exp.line_ctxt == 3);
-	cl_assert(exp.line_adds == 12);
-	cl_assert(exp.line_dels == 4);
+	cl_assert_equal_i(19, exp.lines);
+	cl_assert_equal_i(3, exp.line_ctxt);
+	cl_assert_equal_i(12, exp.line_adds);
+	cl_assert_equal_i(4, exp.line_dels);
 
 	git_diff_list_free(diff);
 
@@ -340,6 +340,145 @@ void test_diff_workdir__filemode_changes_with_filemode_false(void)
 	git_config_free(cfg);
 }
 
+void test_diff_workdir__head_index_and_workdir_all_differ(void)
+{
+	git_diff_options opts = {0};
+	git_diff_list *diff_i2t = NULL, *diff_w2i = NULL;
+	diff_expects exp;
+	char *pathspec = "staged_changes_modified_file";
+	git_tree *tree;
+
+	/* For this file,
+	 * - head->index diff has 1 line of context, 1 line of diff
+	 * - index->workdir diff has 2 lines of context, 1 line of diff
+	 * but
+	 * - head->workdir diff has 1 line of context, 2 lines of diff
+	 * Let's make sure the right one is returned from each fn.
+	 */
+
+	g_repo = cl_git_sandbox_init("status");
+
+	tree = resolve_commit_oid_to_tree(g_repo, "26a125ee1bfc5df1e1b2e9441bbe63c8a7ae989f");
+
+	opts.pathspec.strings = &pathspec;
+	opts.pathspec.count   = 1;
+
+	cl_git_pass(git_diff_index_to_tree(g_repo, &opts, tree, &diff_i2t));
+	cl_git_pass(git_diff_workdir_to_index(g_repo, &opts, &diff_w2i));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff_i2t, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+	cl_assert_equal_i(1, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(0, exp.file_dels);
+	cl_assert_equal_i(1, exp.file_mods);
+	cl_assert_equal_i(1, exp.hunks);
+	cl_assert_equal_i(2, exp.lines);
+	cl_assert_equal_i(1, exp.line_ctxt);
+	cl_assert_equal_i(1, exp.line_adds);
+	cl_assert_equal_i(0, exp.line_dels);
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff_w2i, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+	cl_assert_equal_i(1, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(0, exp.file_dels);
+	cl_assert_equal_i(1, exp.file_mods);
+	cl_assert_equal_i(1, exp.hunks);
+	cl_assert_equal_i(3, exp.lines);
+	cl_assert_equal_i(2, exp.line_ctxt);
+	cl_assert_equal_i(1, exp.line_adds);
+	cl_assert_equal_i(0, exp.line_dels);
+
+	cl_git_pass(git_diff_merge(diff_i2t, diff_w2i));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff_i2t, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+	cl_assert_equal_i(1, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(0, exp.file_dels);
+	cl_assert_equal_i(1, exp.file_mods);
+	cl_assert_equal_i(1, exp.hunks);
+	cl_assert_equal_i(3, exp.lines);
+	cl_assert_equal_i(1, exp.line_ctxt);
+	cl_assert_equal_i(2, exp.line_adds);
+	cl_assert_equal_i(0, exp.line_dels);
+
+	git_diff_list_free(diff_i2t);
+	git_diff_list_free(diff_w2i);
+}
+
+void test_diff_workdir__eof_newline_changes(void)
+{
+	git_diff_options opts = {0};
+	git_diff_list *diff = NULL;
+	diff_expects exp;
+	char *pathspec = "current_file";
+
+	g_repo = cl_git_sandbox_init("status");
+
+	opts.pathspec.strings = &pathspec;
+	opts.pathspec.count   = 1;
+
+	cl_git_pass(git_diff_workdir_to_index(g_repo, &opts, &diff));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+	cl_assert_equal_i(0, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(0, exp.file_dels);
+	cl_assert_equal_i(0, exp.file_mods);
+	cl_assert_equal_i(0, exp.hunks);
+	cl_assert_equal_i(0, exp.lines);
+	cl_assert_equal_i(0, exp.line_ctxt);
+	cl_assert_equal_i(0, exp.line_adds);
+	cl_assert_equal_i(0, exp.line_dels);
+
+	git_diff_list_free(diff);
+
+	cl_git_append2file("status/current_file", "\n");
+
+	cl_git_pass(git_diff_workdir_to_index(g_repo, &opts, &diff));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+	cl_assert_equal_i(1, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(0, exp.file_dels);
+	cl_assert_equal_i(1, exp.file_mods);
+	cl_assert_equal_i(1, exp.hunks);
+	cl_assert_equal_i(2, exp.lines);
+	cl_assert_equal_i(1, exp.line_ctxt);
+	cl_assert_equal_i(1, exp.line_adds);
+	cl_assert_equal_i(0, exp.line_dels);
+
+	git_diff_list_free(diff);
+
+	cl_git_rewritefile("status/current_file", "current_file");
+
+	cl_git_pass(git_diff_workdir_to_index(g_repo, &opts, &diff));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+	cl_assert_equal_i(1, exp.files);
+	cl_assert_equal_i(0, exp.file_adds);
+	cl_assert_equal_i(0, exp.file_dels);
+	cl_assert_equal_i(1, exp.file_mods);
+	cl_assert_equal_i(1, exp.hunks);
+	cl_assert_equal_i(3, exp.lines);
+	cl_assert_equal_i(0, exp.line_ctxt);
+	cl_assert_equal_i(1, exp.line_adds);
+	cl_assert_equal_i(2, exp.line_dels);
+
+	git_diff_list_free(diff);
+}
+
 /* PREPARATION OF TEST DATA
  *
  * Since there is no command line equivalent of git_diff_workdir_to_tree,