branch: deploy git_branch_is_head()

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 {

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;
 
@@ -1345,9 +1346,6 @@ int git_reference_rename(git_reference *ref, const char *new_name, int force)
 	char normalized[GIT_REFNAME_MAX];
 	bool should_head_be_updated = false;
 
-	const char *head_target = NULL;
-	git_reference *head = NULL;
-
 	normalization_flags = ref->flags & GIT_REF_SYMBOLIC ?
 		GIT_REF_FORMAT_ALLOW_ONELEVEL
 		: GIT_REF_FORMAT_NORMAL;
@@ -1370,12 +1368,9 @@ int git_reference_rename(git_reference *ref, const char *new_name, int force)
 	/*
 	 * Check if we have to update HEAD.
 	 */
-	if (git_repository_head(&head, ref->owner) < 0)
+	if ((should_head_be_updated = git_branch_is_head(ref)) < 0)
 		goto cleanup;
 
-	should_head_be_updated = !strcmp(git_reference_name(head), ref->name);
-	git_reference_free(head);
-
 	/*
 	 * Now delete the old ref and remove an possibly existing directory
 	 * named `new_name`. Note that using the internal `reference_delete`