Merge pull request #1138 from ethomson/fetchhead

fetchhead reading/iterating

7 files changed, 472 insertions, 47 deletions

diff --git a/include/git2/errors.h b/include/git2/errors.h
index 63b6bc8ee..8ca900969 100644
--- a/include/git2/errors.h
+++ b/include/git2/errors.h
@@ -63,6 +63,7 @@ typedef enum {
 	GITERR_THREAD,
 	GITERR_STASH,
 	GITERR_CHECKOUT,
+	GITERR_FETCHHEAD,
 } git_error_t;
 
 /**
diff --git a/include/git2/repository.h b/include/git2/repository.h
index 216f59b51..96b47f440 100644
--- a/include/git2/repository.h
+++ b/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.
  *
diff --git a/src/fetchhead.c b/src/fetchhead.c
index ed47bab48..14878feb5 100644
--- a/src/fetchhead.c
+++ b/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)
diff --git a/src/fetchhead.h b/src/fetchhead.h
index ec7c1985b..e694f8aa8 100644
--- a/src/fetchhead.h
+++ b/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);
 
diff --git a/src/util.c b/src/util.c
index 6df32b1c3..059e55dd7 100644
--- a/src/util.c
+++ b/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;
diff --git a/src/util.h b/src/util.h
index cb1c4fdc2..aa193580b 100644
--- a/src/util.h
+++ b/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);
diff --git a/tests-clar/fetchhead/nonetwork.c b/tests-clar/fetchhead/nonetwork.c
index c86ae7402..6ffc6ea2f 100644
--- a/tests-clar/fetchhead/nonetwork.c
+++ b/tests-clar/fetchhead/nonetwork.c
@@ -2,6 +2,7 @@
 
 #include "repository.h"
 #include "fetchhead.h"
+
 #include "fetchhead_data.h"
 
 #define DO_LOCAL_TEST 0
@@ -23,77 +24,286 @@ static void cleanup_repository(void *path)
 	cl_fixture_cleanup((const char *)path);
 }
 
-void test_fetchhead_nonetwork__write(void)
+static void populate_fetchhead(git_vector *out, git_repository *repo)
 {
-	git_vector fetchhead_vector;
-	git_fetchhead_ref *fetchhead[6];
-	git_oid oid[6];
-	git_buf fetchhead_buf = GIT_BUF_INIT;
-	size_t i;
-	int equals = 0;
-
-	git_vector_init(&fetchhead_vector, 6, NULL);
-
-	cl_set_cleanup(&cleanup_repository, "./test1");
+	git_fetchhead_ref *fetchhead_ref;
+	git_oid oid;
 
-	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
-
-	cl_git_pass(git_oid_fromstr(&oid[0],
+	cl_git_pass(git_oid_fromstr(&oid,
 		"49322bb17d3acc9146f98c97d078513228bbf3c0"));
-	cl_git_pass(git_fetchhead_ref_create(&fetchhead[0], &oid[0], 1,
+	cl_git_pass(git_fetchhead_ref_create(&fetchhead_ref, &oid, 1,
 		"refs/heads/master",
 		"git://github.com/libgit2/TestGitRepository"));
-	cl_git_pass(git_vector_insert(&fetchhead_vector, fetchhead[0]));
+	cl_git_pass(git_vector_insert(out, fetchhead_ref));
 
-	cl_git_pass(git_oid_fromstr(&oid[1],
+	cl_git_pass(git_oid_fromstr(&oid,
 		"0966a434eb1a025db6b71485ab63a3bfbea520b6"));
-	cl_git_pass(git_fetchhead_ref_create(&fetchhead[1], &oid[1], 0,
+	cl_git_pass(git_fetchhead_ref_create(&fetchhead_ref, &oid, 0,
 		"refs/heads/first-merge",
 		"git://github.com/libgit2/TestGitRepository"));
-	cl_git_pass(git_vector_insert(&fetchhead_vector, fetchhead[1]));
+	cl_git_pass(git_vector_insert(out, fetchhead_ref));
 
-	cl_git_pass(git_oid_fromstr(&oid[2],
+	cl_git_pass(git_oid_fromstr(&oid,
 		"42e4e7c5e507e113ebbb7801b16b52cf867b7ce1"));
-	cl_git_pass(git_fetchhead_ref_create(&fetchhead[2], &oid[2], 0,
+	cl_git_pass(git_fetchhead_ref_create(&fetchhead_ref, &oid, 0,
 		"refs/heads/no-parent",
 		"git://github.com/libgit2/TestGitRepository"));
-	cl_git_pass(git_vector_insert(&fetchhead_vector, fetchhead[2]));
+	cl_git_pass(git_vector_insert(out, fetchhead_ref));
 
-	cl_git_pass(git_oid_fromstr(&oid[3],
+	cl_git_pass(git_oid_fromstr(&oid,
 		"d96c4e80345534eccee5ac7b07fc7603b56124cb"));
-	cl_git_pass(git_fetchhead_ref_create(&fetchhead[3], &oid[3], 0,
+	cl_git_pass(git_fetchhead_ref_create(&fetchhead_ref, &oid, 0,
 		"refs/tags/annotated_tag",
 		"git://github.com/libgit2/TestGitRepository"));
-	cl_git_pass(git_vector_insert(&fetchhead_vector, fetchhead[3]));
+	cl_git_pass(git_vector_insert(out, fetchhead_ref));
 
-	cl_git_pass(git_oid_fromstr(&oid[4],
+	cl_git_pass(git_oid_fromstr(&oid,
 		"55a1a760df4b86a02094a904dfa511deb5655905"));
-	cl_git_pass(git_fetchhead_ref_create(&fetchhead[4], &oid[4], 0,
+	cl_git_pass(git_fetchhead_ref_create(&fetchhead_ref, &oid, 0,
 		"refs/tags/blob",
 		"git://github.com/libgit2/TestGitRepository"));
-	cl_git_pass(git_vector_insert(&fetchhead_vector, fetchhead[4]));
+	cl_git_pass(git_vector_insert(out, fetchhead_ref));
 
-	cl_git_pass(git_oid_fromstr(&oid[5],
+	cl_git_pass(git_oid_fromstr(&oid,
 		"8f50ba15d49353813cc6e20298002c0d17b0a9ee"));
-	cl_git_pass(git_fetchhead_ref_create(&fetchhead[5], &oid[5], 0,
+	cl_git_pass(git_fetchhead_ref_create(&fetchhead_ref, &oid, 0,
 		"refs/tags/commit_tree",
 		"git://github.com/libgit2/TestGitRepository"));
-	cl_git_pass(git_vector_insert(&fetchhead_vector, fetchhead[5]));
+	cl_git_pass(git_vector_insert(out, fetchhead_ref));
 
-	git_fetchhead_write(g_repo, &fetchhead_vector);
+	cl_git_pass(git_fetchhead_write(repo, out));
+}
+
+void test_fetchhead_nonetwork__write(void)
+{
+	git_vector fetchhead_vector = GIT_VECTOR_INIT;
+	git_fetchhead_ref *fetchhead_ref;
+	git_buf fetchhead_buf = GIT_BUF_INIT;
+	int equals = 0;
+	size_t i;
+
+	git_vector_init(&fetchhead_vector, 6, NULL);
+
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	populate_fetchhead(&fetchhead_vector, g_repo);
 
 	cl_git_pass(git_futils_readbuffer(&fetchhead_buf,
 		"./test1/.git/FETCH_HEAD"));
 
 	equals = (strcmp(fetchhead_buf.ptr, FETCH_HEAD_WILDCARD_DATA) == 0);
 
-	for (i=0; i < 6; i++)
-		git_fetchhead_ref_free(fetchhead[i]);
-
 	git_buf_free(&fetchhead_buf);
 
+	git_vector_foreach(&fetchhead_vector, i, fetchhead_ref) {
+		git_fetchhead_ref_free(fetchhead_ref);
+	}
+
 	git_vector_free(&fetchhead_vector);
 
 	cl_assert(equals);
 }
 
+typedef struct {
+	git_vector *fetchhead_vector;
+	size_t idx;
+} fetchhead_ref_cb_data; 
+
+static int fetchhead_ref_cb(const char *name, const char *url,
+	const git_oid *oid, unsigned int is_merge, void *payload)
+{
+	fetchhead_ref_cb_data *cb_data = payload;
+	git_fetchhead_ref *expected;
+
+	cl_assert(payload);
+
+	expected = git_vector_get(cb_data->fetchhead_vector, cb_data->idx);
+
+	cl_assert(git_oid_cmp(&expected->oid, oid) == 0);
+	cl_assert(expected->is_merge == is_merge);
+
+	if (expected->ref_name)
+		cl_assert(strcmp(expected->ref_name, name) == 0);
+	else
+		cl_assert(name == NULL);
+
+	if (expected->remote_url)
+		cl_assert(strcmp(expected->remote_url, url) == 0);
+	else
+		cl_assert(url == NULL);
+
+	cb_data->idx++;
+
+	return 0;
+}
+
+void test_fetchhead_nonetwork__read(void)
+{
+	git_vector fetchhead_vector = GIT_VECTOR_INIT;
+	git_fetchhead_ref *fetchhead_ref;
+	fetchhead_ref_cb_data cb_data;
+	size_t i;
+
+	memset(&cb_data, 0x0, sizeof(fetchhead_ref_cb_data));
+
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	populate_fetchhead(&fetchhead_vector, g_repo);
+
+	cb_data.fetchhead_vector = &fetchhead_vector;
+
+	cl_git_pass(git_repository_fetchhead_foreach(g_repo, fetchhead_ref_cb, &cb_data));
+
+	git_vector_foreach(&fetchhead_vector, i, fetchhead_ref) {
+		git_fetchhead_ref_free(fetchhead_ref);
+	}
+
+	git_vector_free(&fetchhead_vector);
+}
+
+static int read_old_style_cb(const char *name, const char *url,
+	const git_oid *oid, unsigned int is_merge, void *payload)
+{
+	git_oid expected;
+
+	GIT_UNUSED(payload);
+
+	git_oid_fromstr(&expected, "49322bb17d3acc9146f98c97d078513228bbf3c0");
+
+	cl_assert(name == NULL);
+	cl_assert(url == NULL);
+	cl_assert(git_oid_cmp(&expected, oid) == 0);
+	cl_assert(is_merge == 1);
+
+	return 0;
+}
+
+void test_fetchhead_nonetwork__read_old_style(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\n");
+
+	cl_git_pass(git_repository_fetchhead_foreach(g_repo, read_old_style_cb, NULL));
+}
+
+static int read_type_missing(const char *ref_name, const char *remote_url,
+	const git_oid *oid, unsigned int is_merge, void *payload)
+{
+	git_oid expected;
+
+	GIT_UNUSED(payload);
+
+	git_oid_fromstr(&expected, "49322bb17d3acc9146f98c97d078513228bbf3c0");
+
+	cl_assert(strcmp(ref_name, "name") == 0);
+	cl_assert(strcmp(remote_url, "remote_url") == 0);
+	cl_assert(git_oid_cmp(&expected, oid) == 0);
+	cl_assert(is_merge == 0);
+
+	return 0;
+}
+
+void test_fetchhead_nonetwork__type_missing(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\tnot-for-merge\t'name' of remote_url\n");
+
+	cl_git_pass(git_repository_fetchhead_foreach(g_repo, read_type_missing, NULL));
+}
+
+static int read_name_missing(const char *ref_name, const char *remote_url,
+	const git_oid *oid, unsigned int is_merge, void *payload)
+{
+	git_oid expected;
+
+	GIT_UNUSED(payload);
+
+	git_oid_fromstr(&expected, "49322bb17d3acc9146f98c97d078513228bbf3c0");
+
+	cl_assert(ref_name == NULL);
+	cl_assert(strcmp(remote_url, "remote_url") == 0);
+	cl_assert(git_oid_cmp(&expected, oid) == 0);
+	cl_assert(is_merge == 0);
+
+	return 0;
+}
+
+void test_fetchhead_nonetwork__name_missing(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\tnot-for-merge\tremote_url\n");
+
+	cl_git_pass(git_repository_fetchhead_foreach(g_repo, read_name_missing, NULL));
+}
+
+static int read_noop(const char *ref_name, const char *remote_url,
+	const git_oid *oid, unsigned int is_merge, void *payload)
+{
+	GIT_UNUSED(ref_name);
+	GIT_UNUSED(remote_url);
+	GIT_UNUSED(oid);
+	GIT_UNUSED(is_merge);
+	GIT_UNUSED(payload);
+
+	return 0;
+}
+
+void test_fetchhead_nonetwork__nonexistent(void)
+{
+	int error;
+
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_fail((error = git_repository_fetchhead_foreach(g_repo, read_noop, NULL)));
+	cl_assert(error == GIT_ENOTFOUND);
+}
+
+void test_fetchhead_nonetwork__invalid_unterminated_last_line(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "unterminated");
+	cl_git_fail(git_repository_fetchhead_foreach(g_repo, read_noop, NULL));
+}
+
+void test_fetchhead_nonetwork__invalid_oid(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "shortoid\n");
+	cl_git_fail(git_repository_fetchhead_foreach(g_repo, read_noop, NULL));
+}
+
+void test_fetchhead_nonetwork__invalid_for_merge(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\tinvalid-merge\t\n");
+	cl_git_fail(git_repository_fetchhead_foreach(g_repo, read_noop, NULL));
+
+	cl_assert(git__prefixcmp(giterr_last()->message, "Invalid for-merge") == 0);
+}
+
+void test_fetchhead_nonetwork__invalid_description(void)
+{
+	cl_set_cleanup(&cleanup_repository, "./test1");
+	cl_git_pass(git_repository_init(&g_repo, "./test1", 0));
+
+	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\tnot-for-merge\n");
+	cl_git_fail(git_repository_fetchhead_foreach(g_repo, read_noop, NULL));
+
+	cl_assert(git__prefixcmp(giterr_last()->message, "Invalid description") == 0);
+}
+