Merge pull request #949 from nulltoken/topic/deploy_repository_set_head

Deploy git_repository_set_head()

10 files changed, 292 insertions, 137 deletions

diff --git a/src/branch.c b/src/branch.c
index 103dfe621..6d497b055 100644
--- a/src/branch.c
+++ b/src/branch.c
@@ -92,7 +92,7 @@ cleanup:
 
 int git_branch_delete(git_reference *branch)
 {
-	git_reference *head = NULL;
+	int is_head;
 
 	assert(branch);
 
@@ -102,27 +102,16 @@ int git_branch_delete(git_reference *branch)
 		return -1;
 	}
 
-	if (git_reference_lookup(&head, git_reference_owner(branch), GIT_HEAD_FILE) < 0) {
-		giterr_set(GITERR_REFERENCE, "Cannot locate HEAD.");
-		goto on_error;
-	}
+	if ((is_head = git_branch_is_head(branch)) < 0)
+		return is_head;
 
-	if ((git_reference_type(head) == GIT_REF_SYMBOLIC)
-		&& (strcmp(git_reference_target(head), git_reference_name(branch)) == 0)) {
-			giterr_set(GITERR_REFERENCE,
-					"Cannot delete branch '%s' as it is the current HEAD of the repository.", git_reference_name(branch));
-			goto on_error;
+	if (is_head) {
+		giterr_set(GITERR_REFERENCE,
+				"Cannot delete branch '%s' as it is the current HEAD of the repository.", git_reference_name(branch));
+		return -1;
 	}
 
-	if (git_reference_delete(branch) < 0)
-		goto on_error;
-
-	git_reference_free(head);
-	return 0;
-
-on_error:
-	git_reference_free(head);
-	return -1;
+	return git_reference_delete(branch);
 }
 
 typedef struct {
@@ -271,3 +260,26 @@ cleanup:
 	git_buf_free(&buf);
 	return error;
 }
+
+int git_branch_is_head(
+		git_reference *branch)
+{
+	git_reference *head;
+	bool is_same = false;
+
+	assert(branch);
+
+	if (!git_reference_is_branch(branch))
+		return false;
+
+	if (git_repository_head(&head, git_reference_owner(branch)) < 0)
+		return -1;
+
+	is_same = strcmp(
+		git_reference_name(branch),
+		git_reference_name(head)) == 0;
+
+	git_reference_free(head);
+
+	return is_same;
+}
diff --git a/src/clone.c b/src/clone.c
index 80a13d0f2..a5f4867db 100644
--- a/src/clone.c
+++ b/src/clone.c
@@ -22,112 +22,219 @@
 #include "refs.h"
 #include "path.h"
 
-struct HeadInfo {
-	git_repository *repo;
-	git_oid remote_head_oid;
-	git_buf branchname;
-};
-
-static int create_tracking_branch(git_repository *repo, const git_oid *target, const char *name)
+static int create_branch(
+	git_reference **branch,
+	git_repository *repo,
+	const git_oid *target,
+	const char *name)
 {
 	git_object *head_obj = NULL;
 	git_reference *branch_ref;
-	int retcode = GIT_ERROR;
+	int error;
 
 	/* Find the target commit */
-	if (git_object_lookup(&head_obj, repo, target, GIT_OBJ_ANY) < 0)
-		return GIT_ERROR;
+	if ((error = git_object_lookup(&head_obj, repo, target, GIT_OBJ_ANY)) < 0)
+		return error;
 
 	/* Create the new branch */
-	if (!git_branch_create(&branch_ref, repo, name, head_obj, 0)) {
-		git_config *cfg;
+	error = git_branch_create(&branch_ref, repo, name, head_obj, 0);
 
+	git_object_free(head_obj);
+
+	if (!error)
+		*branch = branch_ref;
+	else
 		git_reference_free(branch_ref);
-		/* Set up tracking */
-		if (!git_repository_config(&cfg, repo)) {
-			git_buf remote = GIT_BUF_INIT;
-			git_buf merge = GIT_BUF_INIT;
-			git_buf merge_target = GIT_BUF_INIT;
-			if (!git_buf_printf(&remote, "branch.%s.remote", name) &&
-				 !git_buf_printf(&merge, "branch.%s.merge", name) &&
-				 !git_buf_printf(&merge_target, "refs/heads/%s", name) &&
-				 !git_config_set_string(cfg, git_buf_cstr(&remote), "origin") &&
-				 !git_config_set_string(cfg, git_buf_cstr(&merge), git_buf_cstr(&merge_target))) {
-				retcode = 0;
-			}
-			git_buf_free(&remote);
-			git_buf_free(&merge);
-			git_buf_free(&merge_target);
-			git_config_free(cfg);
-		}
-	}
 
-	git_object_free(head_obj);
-	return retcode;
+	return error;
 }
 
-static int reference_matches_remote_head(const char *head_name, void *payload)
+static int setup_tracking_config(
+	git_repository *repo,
+	const char *branch_name,
+	const char *remote_name,
+	const char *merge_target)
 {
-	struct HeadInfo *head_info = (struct HeadInfo *)payload;
+	git_config *cfg;
+	git_buf remote_key = GIT_BUF_INIT, merge_key = GIT_BUF_INIT;
+	int error = -1;
+
+	if (git_repository_config__weakptr(&cfg, repo) < 0)
+		return -1;
+
+	if (git_buf_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
+		goto cleanup;
+
+	if (git_buf_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
+		goto cleanup;
+
+	if (git_config_set_string(cfg, git_buf_cstr(&remote_key), remote_name) < 0)
+		goto cleanup;
+
+	if (git_config_set_string(cfg, git_buf_cstr(&merge_key), merge_target) < 0)
+		goto cleanup;
+
+	error = 0;
+
+cleanup:
+	git_buf_free(&remote_key);
+	git_buf_free(&merge_key);
+	return error;
+}
+
+static int create_tracking_branch(
+	git_reference **branch,
+	git_repository *repo,
+	const git_oid *target,
+	const char *branch_name)
+{
+	int error;
+
+	if ((error = create_branch(branch, repo, target, branch_name)) < 0)
+		return error;
+
+	return setup_tracking_config(
+		repo,
+		branch_name,
+		GIT_REMOTE_ORIGIN,
+		git_reference_name(*branch));
+}
+
+struct head_info {
+	git_repository *repo;
+	git_oid remote_head_oid;
+	git_buf branchname;
+	const git_refspec *refspec;
+};
+
+static int reference_matches_remote_head(
+	const char *reference_name,
+	void *payload)
+{
+	struct head_info *head_info = (struct head_info *)payload;
 	git_oid oid;
 
+	/* TODO: Should we guard against references
+	 * which name doesn't start with refs/heads/ ?
+	 */
+
 	/* Stop looking if we've already found a match */
-	if (git_buf_len(&head_info->branchname) > 0) return 0;
+	if (git_buf_len(&head_info->branchname) > 0)
+		return 0;
+
+	if (git_reference_name_to_oid(
+		&oid,
+		head_info->repo,
+		reference_name) < 0) {
+			/* TODO: How to handle not found references?
+			 */
+			return -1;
+	}
 
-	if (!git_reference_name_to_oid(&oid, head_info->repo, head_name) &&
-		 !git_oid_cmp(&head_info->remote_head_oid, &oid)) {
-		git_buf_puts(&head_info->branchname,
-						 head_name+strlen("refs/remotes/origin/"));
+	if (git_oid_cmp(&head_info->remote_head_oid, &oid) == 0) {
+		/* Determine the local reference name from the remote tracking one */
+		if (git_refspec_transform_l(
+			&head_info->branchname, 
+			head_info->refspec,
+			reference_name) < 0)
+				return -1;
+		
+		if (git_buf_sets(
+			&head_info->branchname,
+			git_buf_cstr(&head_info->branchname) + strlen(GIT_REFS_HEADS_DIR)) < 0)
+				return -1;
 	}
+
 	return 0;
 }
 
-static int update_head_to_new_branch(git_repository *repo, const git_oid *target, const char *name)
+static int update_head_to_new_branch(
+	git_repository *repo,
+	const git_oid *target,
+	const char *name)
 {
-	int retcode = GIT_ERROR;
+	git_reference *tracking_branch;
+	int error;
 
-	if (!create_tracking_branch(repo, target, name)) {
-		git_reference *head;
-		if (!git_reference_lookup(&head, repo, GIT_HEAD_FILE)) {
-			git_buf targetbuf = GIT_BUF_INIT;
-			if (!git_buf_printf(&targetbuf, "refs/heads/%s", name)) {
-				retcode = git_reference_set_target(head, git_buf_cstr(&targetbuf));
-			}
-			git_buf_free(&targetbuf);
-			git_reference_free(head);
-		}
-	}
+	if ((error = create_tracking_branch(
+		&tracking_branch,
+		repo,
+		target,
+		name)) < 0)
+			return error;
 
-	return retcode;
+	error = git_repository_set_head(repo, git_reference_name(tracking_branch));
+
+	git_reference_free(tracking_branch);
+
+	return error;
 }
 
 static int update_head_to_remote(git_repository *repo, git_remote *remote)
 {
-	int retcode = GIT_ERROR;
+	int retcode = -1;
 	git_remote_head *remote_head;
-	git_oid oid;
-	struct HeadInfo head_info;
+	struct head_info head_info;
+	git_buf remote_master_name = GIT_BUF_INIT;
+
+	/* Did we just clone an empty repository? */
+	if (remote->refs.length == 0) {
+		return setup_tracking_config(
+			repo,
+			"master",
+			GIT_REMOTE_ORIGIN,
+			GIT_REFS_HEADS_MASTER_FILE);
+	}
 
 	/* Get the remote's HEAD. This is always the first ref in remote->refs. */
 	remote_head = remote->refs.contents[0];
 	git_oid_cpy(&head_info.remote_head_oid, &remote_head->oid);
 	git_buf_init(&head_info.branchname, 16);
 	head_info.repo = repo;
-
-	/* Check to see if "master" matches the remote head */
-	if (!git_reference_name_to_oid(&oid, repo, "refs/remotes/origin/master") &&
-		 !git_oid_cmp(&remote_head->oid, &oid)) {
-		retcode = update_head_to_new_branch(repo, &oid, "master");
+	head_info.refspec = git_remote_fetchspec(remote);
+	
+	/* Determine the remote tracking reference name from the local master */
+	if (git_refspec_transform_r(
+		&remote_master_name,
+		head_info.refspec,
+		GIT_REFS_HEADS_MASTER_FILE) < 0)
+			return -1;
+
+	/* Check to see if the remote HEAD points to the remote master */
+	if (reference_matches_remote_head(git_buf_cstr(&remote_master_name), &head_info) < 0)
+		goto cleanup;
+
+	if (git_buf_len(&head_info.branchname) > 0) {
+		retcode = update_head_to_new_branch(
+			repo,
+			&head_info.remote_head_oid,
+			git_buf_cstr(&head_info.branchname));
+
+		goto cleanup;
 	}
+
 	/* Not master. Check all the other refs. */
-	else if (!git_reference_foreach(repo, GIT_REF_LISTALL,
-												 reference_matches_remote_head,
-												 &head_info) &&
-				git_buf_len(&head_info.branchname) > 0) {
-		retcode = update_head_to_new_branch(repo, &head_info.remote_head_oid,
-														git_buf_cstr(&head_info.branchname));
+	if (git_reference_foreach(
+		repo,
+		GIT_REF_LISTALL,
+		reference_matches_remote_head,
+		&head_info) < 0)
+			goto cleanup;
+
+	if (git_buf_len(&head_info.branchname) > 0) {
+		retcode = update_head_to_new_branch(
+			repo,
+			&head_info.remote_head_oid,
+			git_buf_cstr(&head_info.branchname));
+
+		goto cleanup;
+	} else {
+		/* TODO: What should we do if nothing has been found?
+		 */
 	}
 
+cleanup:
+	git_buf_free(&remote_master_name);
 	git_buf_free(&head_info.branchname);
 	return retcode;
 }
@@ -150,7 +257,7 @@ static int setup_remotes_and_fetch(git_repository *repo,
 	if (!fetch_stats) fetch_stats = &dummy_stats;
 
 	/* Create the "origin" remote */
-	if (!git_remote_add(&origin, repo, "origin", origin_url)) {
+	if (!git_remote_add(&origin, repo, GIT_REMOTE_ORIGIN, origin_url)) {
 		/* Connect and download everything */
 		if (!git_remote_connect(origin, GIT_DIR_FETCH)) {
 			if (!git_remote_download(origin, &bytes, fetch_stats)) {
@@ -184,11 +291,14 @@ static bool path_is_okay(const char *path)
 }
 
 
-static int clone_internal(git_repository **out,
-								  const char *origin_url,
-								  const char *path,
-								  git_indexer_stats *fetch_stats,
-								  int is_bare)
+static int clone_internal(
+	git_repository **out,
+	const char *origin_url,
+	const char *path,
+	git_indexer_stats *fetch_stats,
+	git_indexer_stats *checkout_stats,
+	git_checkout_opts *checkout_opts,
+	int is_bare)
 {
 	int retcode = GIT_ERROR;
 	git_repository *repo = NULL;
@@ -211,6 +321,9 @@ static int clone_internal(git_repository **out,
 		}
 	}
 
+	if (!retcode && !is_bare && !git_repository_head_orphan(repo))
+		retcode = git_checkout_head(*out, checkout_opts, checkout_stats);
+
 	return retcode;
 }
 
@@ -220,7 +333,15 @@ int git_clone_bare(git_repository **out,
 						 git_indexer_stats *fetch_stats)
 {
 	assert(out && origin_url && dest_path);
-	return clone_internal(out, origin_url, dest_path, fetch_stats, 1);
+
+	return clone_internal(
+		out,
+		origin_url,
+		dest_path,
+		fetch_stats,
+		NULL,
+		NULL,
+		1);
 }
 
 
@@ -231,12 +352,14 @@ int git_clone(git_repository **out,
 				  git_indexer_stats *checkout_stats,
 				  git_checkout_opts *checkout_opts)
 {
-	int retcode = GIT_ERROR;
-
 	assert(out && origin_url && workdir_path);
 
-	if (!(retcode = clone_internal(out, origin_url, workdir_path, fetch_stats, 0)))
-		retcode = git_checkout_head(*out, checkout_opts, checkout_stats);
-
-	return retcode;
+	return clone_internal(
+		out,
+		origin_url,
+		workdir_path,
+		fetch_stats,
+		checkout_stats,
+		checkout_opts,
+		0);
 }
diff --git a/src/refs.c b/src/refs.c
index bd6fbee0e..9dc422e1b 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -15,6 +15,7 @@
 #include <git2/tag.h>
 #include <git2/object.h>
 #include <git2/oid.h>
+#include <git2/branch.h>
 
 GIT__USE_STRMAP;
 
@@ -1343,9 +1344,7 @@ int git_reference_rename(git_reference *ref, const char *new_name, int force)
 	unsigned int normalization_flags;
 	git_buf aux_path = GIT_BUF_INIT;
 	char normalized[GIT_REFNAME_MAX];
-
-	const char *head_target = NULL;
-	git_reference *head = NULL;
+	bool should_head_be_updated = false;
 
 	normalization_flags = ref->flags & GIT_REF_SYMBOLIC ?
 		GIT_REF_FORMAT_ALLOW_ONELEVEL
@@ -1367,6 +1366,12 @@ int git_reference_rename(git_reference *ref, const char *new_name, int force)
 		return -1;
 
 	/*
+	 * Check if we have to update HEAD.
+	 */
+	if ((should_head_be_updated = git_branch_is_head(ref)) < 0)
+		goto cleanup;
+
+	/*
 	 * Now delete the old ref and remove an possibly existing directory
 	 * named `new_name`. Note that using the internal `reference_delete`
 	 * method deletes the ref from disk but doesn't free the pointer, so
@@ -1390,25 +1395,13 @@ int git_reference_rename(git_reference *ref, const char *new_name, int force)
 		goto rollback;
 
 	/*
-	 * Check if we have to update HEAD.
+	 * Update HEAD it was poiting to the reference being renamed.
 	 */
-	if (git_reference_lookup(&head, ref->owner, GIT_HEAD_FILE) < 0) {
-		giterr_set(GITERR_REFERENCE,
-			"Failed to update HEAD after renaming reference");
-		goto cleanup;
-	}
-
-	head_target = git_reference_target(head);
-
-	if (head_target && !strcmp(head_target, ref->name)) {
-		git_reference_free(head);
-		head = NULL;
-
-		if (git_reference_create_symbolic(&head, ref->owner, "HEAD", new_name, 1) < 0) {
+	if (should_head_be_updated && 
+		git_repository_set_head(ref->owner, new_name) < 0) {
 			giterr_set(GITERR_REFERENCE,
 				"Failed to update HEAD after renaming reference");
 			goto cleanup;
-		}
 	}
 
 	/*
@@ -1426,12 +1419,10 @@ int git_reference_rename(git_reference *ref, const char *new_name, int force)
 	/* The reference is no longer packed */
 	ref->flags &= ~GIT_REF_PACKED;
 
-	git_reference_free(head);
 	git_buf_free(&aux_path);
 	return 0;
 
 cleanup:
-	git_reference_free(head);
 	git_buf_free(&aux_path);
 	return -1;
 
diff --git a/src/refspec.c b/src/refspec.c
index cd3a528bd..b1790b32c 100644
--- a/src/refspec.c
+++ b/src/refspec.c
@@ -194,20 +194,20 @@ int git_refspec_transform(char *out, size_t outlen, const git_refspec *spec, con
 	return 0;
 }
 
-int git_refspec_transform_r(git_buf *out, const git_refspec *spec, const char *name)
+static int refspec_transform(git_buf *out, const char *from, const char *to, const char *name)
 {
-	if (git_buf_sets(out, spec->dst) < 0)
+	if (git_buf_sets(out, to) < 0)
 		return -1;
 
 	/*
-	 * No '*' at the end means that it's mapped to one specific local
+	 * No '*' at the end means that it's mapped to one specific
 	 * branch, so no actual transformation is needed.
 	 */
 	if (git_buf_len(out) > 0 && out->ptr[git_buf_len(out) - 1] != '*')
 		return 0;
 
 	git_buf_truncate(out, git_buf_len(out) - 1); /* remove trailing '*' */
-	git_buf_puts(out, name + strlen(spec->src) - 1);
+	git_buf_puts(out, name + strlen(from) - 1);
 
 	if (git_buf_oom(out))
 		return -1;
@@ -215,3 +215,13 @@ int git_refspec_transform_r(git_buf *out, const git_refspec *spec, const char *n
 	return 0;
 }
 
+int git_refspec_transform_r(git_buf *out, const git_refspec *spec, const char *name)
+{
+	return refspec_transform(out, spec->src, spec->dst, name);
+}
+
+int git_refspec_transform_l(git_buf *out, const git_refspec *spec, const char *name)
+{
+	return refspec_transform(out, spec->dst, spec->src, name);
+}
+
diff --git a/src/refspec.h b/src/refspec.h
index a5df458c6..6e0596a55 100644
--- a/src/refspec.h
+++ b/src/refspec.h
@@ -40,4 +40,15 @@ void git_refspec__free(git_refspec *refspec);
  */
 int git_refspec_transform_r(git_buf *out, const git_refspec *spec, const char *name);
 
+/**
+ * Transform a reference from its target following the refspec's rules,
+ * and writes the results into a git_buf.
+ *
+ * @param out where to store the source name
+ * @param spec the refspec
+ * @param name the name of the reference to transform
+ * @return 0 or error if buffer allocation fails
+ */
+int git_refspec_transform_l(git_buf *out, const git_refspec *spec, const char *name);
+
 #endif
diff --git a/src/remote.h b/src/remote.h
index b8bb2c55d..05073db8c 100644
--- a/src/remote.h
+++ b/src/remote.h
@@ -13,6 +13,8 @@
 #include "transport.h"
 #include "repository.h"
 
+#define GIT_REMOTE_ORIGIN "origin"
+
 struct git_remote {
 	char *name;
 	char *url;
diff --git a/src/repository.c b/src/repository.c
index 1a46db0a5..1b49228fb 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -19,6 +19,7 @@
 #include "refs.h"
 #include "filter.h"
 #include "odb.h"
+#include "remote.h"
 
 #define GIT_FILE_CONTENT_PREFIX "gitdir:"
 
@@ -654,10 +655,10 @@ static int repo_init_create_head(const char *git_dir, const char *ref_name)
 	if (!ref_name)
 		ref_name = GIT_BRANCH_MASTER;
 
-	if (git__prefixcmp(ref_name, "refs/") == 0)
+	if (git__prefixcmp(ref_name, GIT_REFS_DIR) == 0)
 		fmt = "ref: %s\n";
 	else
-		fmt = "ref: refs/heads/%s\n";
+		fmt = "ref: " GIT_REFS_HEADS_DIR "%s\n";
 
 	if (git_filebuf_printf(&ref, fmt, ref_name) < 0 ||
 		git_filebuf_commit(&ref, GIT_REFS_FILE_MODE) < 0)
@@ -1095,7 +1096,7 @@ static int repo_init_create_origin(git_repository *repo, const char *url)
 	int error;
 	git_remote *remote;
 
-	if (!(error = git_remote_add(&remote, repo, "origin", url))) {
+	if (!(error = git_remote_add(&remote, repo, GIT_REMOTE_ORIGIN, url))) {
 		error = git_remote_save(remote);
 		git_remote_free(remote);
 	}
@@ -1219,7 +1220,7 @@ int git_repository_is_empty(git_repository *repo)
 	git_reference *head = NULL, *branch = NULL;
 	int error;
 
-	if (git_reference_lookup(&head, repo, "HEAD") < 0)
+	if (git_reference_lookup(&head, repo, GIT_HEAD_FILE) < 0)
 		return -1;
 
 	if (git_reference_type(head) != GIT_REF_SYMBOLIC) {
@@ -1227,7 +1228,7 @@ int git_repository_is_empty(git_repository *repo)
 		return 0;
 	}
 
-	if (strcmp(git_reference_target(head), "refs/heads/master") != 0) {
+	if (strcmp(git_reference_target(head), GIT_REFS_HEADS_DIR "master") != 0) {
 		git_reference_free(head);
 		return 0;
 	}
diff --git a/src/reset.c b/src/reset.c
index 4ce21e2cf..c536e75b8 100644
--- a/src/reset.c
+++ b/src/reset.c
@@ -29,6 +29,7 @@ int git_reset(
 	git_tree *tree = NULL;
 	int error = -1;
 	git_checkout_opts opts;
+	git_reference *head = NULL;
 
 	assert(repo && target);
 	assert(reset_type == GIT_RESET_SOFT
@@ -49,7 +50,10 @@ int git_reset(
 
 	//TODO: Check for unmerged entries
 
-	if (git_reference__update(repo, git_object_id(commit), GIT_HEAD_FILE) < 0)
+	if (git_repository_head(&head, repo) < 0)
+		goto cleanup;
+
+	if (git_reference_set_oid(head, git_object_id(commit)) < 0)
 		goto cleanup;
 
 	if (reset_type == GIT_RESET_SOFT) {
@@ -96,6 +100,7 @@ int git_reset(
 	error = 0;
 
 cleanup:
+	git_reference_free(head);
 	git_object_free(commit);
 	git_index_free(index);
 	git_tree_free(tree);
diff --git a/src/revparse.c b/src/revparse.c
index 5e2db99cd..191f6374c 100644
--- a/src/revparse.c
+++ b/src/revparse.c
@@ -28,11 +28,11 @@ static int disambiguate_refname(git_reference **out, git_repository *repo, const
 
 	static const char* formatters[] = {
 		"%s",
-		"refs/%s",
-		"refs/tags/%s",
-		"refs/heads/%s",
-		"refs/remotes/%s",
-		"refs/remotes/%s/HEAD",
+		GIT_REFS_DIR "%s",
+		GIT_REFS_TAGS_DIR "%s",
+		GIT_REFS_HEADS_DIR "%s",
+		GIT_REFS_REMOTES_DIR "%s",
+		GIT_REFS_REMOTES_DIR "%s/" GIT_HEAD_FILE,
 		NULL
 	};
 
@@ -520,7 +520,7 @@ static int handle_grep_syntax(git_object **out, git_repository *repo, const git_
 
 	if (spec_oid == NULL) {
 		// TODO: @carlosmn: The glob should be refs/* but this makes git_revwalk_next() fails
-		if (git_revwalk_push_glob(walk, "refs/heads/*") < 0)
+		if (git_revwalk_push_glob(walk, GIT_REFS_HEADS_DIR "*") < 0)
 			goto cleanup;
 	} else if (git_revwalk_push(walk, spec_oid) < 0)
 			goto cleanup;
diff --git a/src/submodule.c b/src/submodule.c
index a2162496a..180528641 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -1315,7 +1315,7 @@ static int lookup_head_remote(git_buf *url, git_repository *repo)
 	/* remote should refer to something like refs/remotes/ORIGIN/BRANCH */
 
 	if (git_reference_type(remote) != GIT_REF_SYMBOLIC ||
-		git__prefixcmp(git_reference_target(remote), "refs/remotes/") != 0)
+		git__prefixcmp(git_reference_target(remote), GIT_REFS_REMOTES_DIR) != 0)
 	{
 		giterr_set(GITERR_SUBMODULE,
 			"Cannot resolve relative URL when HEAD is not symbolic");
@@ -1323,7 +1323,7 @@ static int lookup_head_remote(git_buf *url, git_repository *repo)
 		goto cleanup;
 	}
 
-	scan = tgt = git_reference_target(remote) + strlen("refs/remotes/");
+	scan = tgt = git_reference_target(remote) + strlen(GIT_REFS_REMOTES_DIR);
 	while (*scan && (*scan != '/' || (scan > tgt && scan[-1] != '\\')))
 		scan++; /* find non-escaped slash to end ORIGIN name */