fetchhead reading/iterating

include/git2/errors.h

@@ -63,6 +63,7 @@ typedef enum {
 	GITERR_THREAD,
 	GITERR_STASH,
 	GITERR_CHECKOUT,
+	GITERR_FETCHHEAD,
 } git_error_t;
 
 /**

include/git2/repository.h

@@ -490,6 +490,24 @@ GIT_EXTERN(int) git_repository_message(char *out, size_t len, git_repository *re
  */
 GIT_EXTERN(int) git_repository_message_remove(git_repository *repo);
 
+typedef int (*git_repository_fetchhead_foreach_cb)(const char *ref_name,
+	const char *remote_url,
+	const git_oid *oid,
+	unsigned int is_merge,
+	void *payload);
+
+/**
+ * Call callback 'callback' for each entry in the given FETCH_HEAD file.
+ *
+ * @param repo A repository object
+ * @param callback Callback function
+ * @param payload Pointer to callback data (optional)
+ * @return 0 on success, GIT_ENOTFOUND, GIT_EUSER or error
+ */
+GIT_EXTERN(int) git_repository_fetchhead_foreach(git_repository *repo,
+	git_repository_fetchhead_foreach_cb callback,
+	void *payload);
+
 /**
  * Calculate hash of file using repository filtering rules.
  *

src/fetchhead.c

@@ -10,6 +10,7 @@
 
 #include "fetchhead.h"
 #include "common.h"
+#include "buffer.h"
 #include "fileops.h"
 #include "filebuf.h"
 #include "refs.h"
@@ -26,19 +27,28 @@ int git_fetchhead_ref_cmp(const void *a, const void *b)
 	if (two->is_merge && !one->is_merge)
 		return 1;
 
-	return strcmp(one->ref_name, two->ref_name);
+	if (one->ref_name && two->ref_name)
+		return strcmp(one->ref_name, two->ref_name);
+	else if (one->ref_name)
+		return -1;
+	else if (two->ref_name)
+		return 1;
+
+	return 0;
 }
 
 int git_fetchhead_ref_create(
-	git_fetchhead_ref **fetchhead_ref_out,
+	git_fetchhead_ref **out,
 	git_oid *oid,
-	int is_merge,
+	unsigned int is_merge,
 	const char *ref_name,
 	const char *remote_url)
 {
-	git_fetchhead_ref *fetchhead_ref = NULL;
+	git_fetchhead_ref *fetchhead_ref;
+
+	assert(out && oid);
 
-	assert(fetchhead_ref_out && oid && ref_name && remote_url);
+	*out = NULL;
 
 	fetchhead_ref = git__malloc(sizeof(git_fetchhead_ref));
 	GITERR_CHECK_ALLOC(fetchhead_ref);
@@ -47,10 +57,14 @@ int git_fetchhead_ref_create(
 
 	git_oid_cpy(&fetchhead_ref->oid, oid);
 	fetchhead_ref->is_merge = is_merge;
-	fetchhead_ref->ref_name = git__strdup(ref_name);
-	fetchhead_ref->remote_url = git__strdup(remote_url);
 
-	*fetchhead_ref_out = fetchhead_ref;
+	if (ref_name)
+		fetchhead_ref->ref_name = git__strdup(ref_name);
+
+	if (remote_url)
+		fetchhead_ref->remote_url = git__strdup(remote_url);
+
+	*out = fetchhead_ref;
 
 	return 0;
 }
@@ -114,6 +128,162 @@ int git_fetchhead_write(git_repository *repo, git_vector *fetchhead_refs)
 	return git_filebuf_commit(&file, GIT_REFS_FILE_MODE);
 }
 
+static int fetchhead_ref_parse(
+	git_oid *oid,
+	unsigned int *is_merge,
+	git_buf *ref_name,
+	const char **remote_url,
+	char *line,
+	size_t line_num)
+{
+	char *oid_str, *is_merge_str, *desc, *name = NULL;
+	const char *type = NULL;
+	int error = 0;
+
+	*remote_url = NULL;
+
+	if (!*line) {
+		giterr_set(GITERR_FETCHHEAD,
+			"Empty line in FETCH_HEAD line %d", line_num);
+		return -1;
+	}
+
+	/* Compat with old git clients that wrote FETCH_HEAD like a loose ref. */
+	if ((oid_str = git__strsep(&line, "\t")) == NULL) {
+		oid_str = line;
+		line += strlen(line);
+
+		*is_merge = 1;
+	}
+
+	if (strlen(oid_str) != GIT_OID_HEXSZ) {
+		giterr_set(GITERR_FETCHHEAD,
+			"Invalid object ID in FETCH_HEAD line %d", line_num);
+		return -1;
+	}
+
+	if (git_oid_fromstr(oid, oid_str) < 0) {
+		const git_error *oid_err = giterr_last();
+		const char *err_msg = oid_err ? oid_err->message : "Invalid object ID";
+
+		giterr_set(GITERR_FETCHHEAD, "%s in FETCH_HEAD line %d",
+			err_msg, line_num);
+		return -1;
+	}
+
+	/* Parse new data from newer git clients */
+	if (*line) {
+		if ((is_merge_str = git__strsep(&line, "\t")) == NULL) {
+			giterr_set(GITERR_FETCHHEAD,
+				"Invalid description data in FETCH_HEAD line %d", line_num);
+			return -1;
+		}
+
+		if (*is_merge_str == '\0')
+			*is_merge = 1;
+		else if (strcmp(is_merge_str, "not-for-merge") == 0)
+			*is_merge = 0;
+		else {
+			giterr_set(GITERR_FETCHHEAD,
+				"Invalid for-merge entry in FETCH_HEAD line %d", line_num);
+			return -1;
+		}
+
+		if ((desc = line) == NULL) {
+			giterr_set(GITERR_FETCHHEAD,
+				"Invalid description in FETCH_HEAD line %d", line_num);
+			return -1;
+		}
+
+		if (git__prefixcmp(desc, "branch '") == 0) {
+			type = GIT_REFS_HEADS_DIR;
+			name = desc + 8;
+		} else if (git__prefixcmp(desc, "tag '") == 0) {
+			type = GIT_REFS_TAGS_DIR;
+			name = desc + 5;
+		} else if (git__prefixcmp(desc, "'") == 0)
+			name = desc + 1;
+
+		if (name) {
+			if ((desc = strchr(name, '\'')) == NULL ||
+				git__prefixcmp(desc, "' of ") != 0) {
+				giterr_set(GITERR_FETCHHEAD,
+					"Invalid description in FETCH_HEAD line %d", line_num);
+				return -1;
+			}
+
+			*desc = '\0';
+			desc += 5;
+		}
+
+		*remote_url = desc;
+	}
+
+	git_buf_clear(ref_name);
+
+	if (type)
+		git_buf_join(ref_name, '/', type, name);
+	else if(name)
+		git_buf_puts(ref_name, name);
+
+	return error;
+}
+
+int git_repository_fetchhead_foreach(git_repository *repo,
+	git_repository_fetchhead_foreach_cb cb,
+	void *payload)
+{
+	git_buf path = GIT_BUF_INIT, file = GIT_BUF_INIT, name = GIT_BUF_INIT;
+	const char *ref_name;
+	git_oid oid;
+	const char *remote_url;
+	unsigned int is_merge;
+	char *buffer, *line;
+	size_t line_num = 0;
+	int error = 0;
+
+	assert(repo && cb);
+
+	if (git_buf_joinpath(&path, repo->path_repository, GIT_FETCH_HEAD_FILE) < 0)
+		return -1;
+
+	if ((error = git_futils_readbuffer(&file, git_buf_cstr(&path))) < 0)
+		goto done;
+
+	buffer = file.ptr;
+
+	while ((line = git__strsep(&buffer, "\n")) != NULL) {
+		++line_num;
+
+		if ((error = fetchhead_ref_parse(&oid, &is_merge, &name, &remote_url,
+			line, line_num)) < 0)
+			goto done;
+
+		if (git_buf_len(&name) > 0)
+			ref_name = git_buf_cstr(&name);
+		else
+			ref_name = NULL;
+
+		if ((cb(ref_name, remote_url, &oid, is_merge, payload)) != 0) {
+			error = GIT_EUSER;
+			goto done;
+		}
+	}
+
+	if (*buffer) {
+		giterr_set(GITERR_FETCHHEAD, "No EOL at line %d", line_num+1);
+		error = -1;
+		goto done;
+	}
+
+done:
+	git_buf_free(&file);
+	git_buf_free(&path);
+	git_buf_free(&name);
+
+	return error;
+}
+
 void git_fetchhead_ref_free(git_fetchhead_ref *fetchhead_ref)
 {
 	if (fetchhead_ref == NULL)

src/fetchhead.h

@@ -9,18 +9,25 @@
 
 #include "vector.h"
 
-typedef struct git_fetchhead_ref {
+struct git_fetchhead_ref {
 	git_oid oid;
 	unsigned int is_merge;
 	char *ref_name;
 	char *remote_url;
-} git_fetchhead_ref;
+};
 
-int git_fetchhead_ref_create(git_fetchhead_ref **fetchhead_ref_out, git_oid *oid, int is_merge, const char *ref_name, const char *remote_url);
+typedef struct git_fetchhead_ref git_fetchhead_ref;
+
+int git_fetchhead_ref_create(
+	git_fetchhead_ref **fetchhead_ref_out,
+	git_oid *oid,
+	unsigned int is_merge,
+	const char *ref_name,
+	const char *remote_url);
 
 int git_fetchhead_ref_cmp(const void *a, const void *b);
 
-int git_fetchhead_write(git_repository *repository, git_vector *fetchhead_refs);
+int git_fetchhead_write(git_repository *repo, git_vector *fetchhead_refs);
 
 void git_fetchhead_ref_free(git_fetchhead_ref *fetchhead_ref);
 

src/util.c

@@ -276,6 +276,24 @@ char *git__strtok(char **end, const char *sep)
 	return NULL;
 }
 
+/* Similar to strtok, but does not collapse repeated tokens. */
+char *git__strsep(char **end, const char *sep)
+{
+	char *start = *end, *ptr = *end;
+
+	while (*ptr && !strchr(sep, *ptr))
+		++ptr;
+
+	if (*ptr) {
+		*end = ptr + 1;
+		*ptr = '\0';
+
+		return start;
+	}
+
+	return NULL;
+}
+
 void git__hexdump(const char *buffer, size_t len)
 {
 	static const size_t LINE_WIDTH = 16;

src/util.h

@@ -107,6 +107,7 @@ GIT_INLINE(int) git__is_sizet(git_off_t p)
 #endif
 
 extern char *git__strtok(char **end, const char *sep);
+extern char *git__strsep(char **end, const char *sep);
 
 extern void git__strntolower(char *str, size_t len);
 extern void git__strtolower(char *str);