revwalk: allow pushing/hiding a reference by name

The code was already there, so factor it out and let users push an OID
by giving it a reference name. Only refs to commits are
supported. Annotated tags will throw an error.

include/git2/revwalk.h

@@ -164,6 +164,28 @@ GIT_EXTERN(int) git_revwalk_hide_glob(git_revwalk *walk, const char *glob);
 GIT_EXTERN(int) git_revwalk_hide_head(git_revwalk *walk);
 
 /**
+ * Push the OID pointed to by a reference
+ *
+ * The reference must point to a commit.
+ *
+ * @param walk the walker being used for the traversal
+ * @param refname the referece to push
+ * @return GIT_SUCCESS or an error code
+ */
+GIT_EXTERN(int) git_revwalk_push_ref(git_revwalk *walk, const char *refname);
+
+/**
+ * Hide the OID pointed to by a reference
+ *
+ * The reference must point to a commit.
+ *
+ * @param walk the walker being used for the traversal
+ * @param refname the referece to hide
+ * @return GIT_SUCCESS or an error code
+ */
+GIT_EXTERN(int) git_revwalk_hide_ref(git_revwalk *walk, const char *refname);
+
+/**
  * Get the next commit from the revision walk.
  *
  * The initial call to this method is *not* blocking when

src/revwalk.c

@@ -310,31 +310,35 @@ int git_revwalk_hide(git_revwalk *walk, const git_oid *oid)
 	return push_commit(walk, oid, 1);
 }
 
-struct push_cb_data {
-	git_revwalk *walk;
-	const char *glob;
-	int hide;
-};
-
-static int push_glob_cb(const char *refname, void *data_)
+static int push_ref(git_revwalk *walk, const char *refname, int hide)
 {
-	struct push_cb_data *data = (struct push_cb_data *)data_;
-
-	if (!git__fnmatch(data->glob, refname, 0)) {
 	git_reference *ref, *resolved;
 	int error;
 
-		error = git_reference_lookup(&ref, data->walk->repo, refname);
+	error = git_reference_lookup(&ref, walk->repo, refname);
 	if (error < GIT_SUCCESS)
 		return error;
 	error = git_reference_resolve(&resolved, ref);
 	git_reference_free(ref);
 	if (error < GIT_SUCCESS)
 		return error;
-		error = push_commit(data->walk, git_reference_oid(resolved), data->hide);
+	error = push_commit(walk, git_reference_oid(resolved), hide);
 	git_reference_free(resolved);
 	return error;
-	}
+}
+
+struct push_cb_data {
+	git_revwalk *walk;
+	const char *glob;
+	int hide;
+};
+
+static int push_glob_cb(const char *refname, void *data_)
+{
+	struct push_cb_data *data = (struct push_cb_data *)data_;
+
+	if (!git__fnmatch(data->glob, refname, 0))
+		return push_ref(data->walk, refname, data->hide);
 
 	return GIT_SUCCESS;
 }
@@ -394,37 +398,28 @@ int git_revwalk_hide_glob(git_revwalk *walk, const char *glob)
 	return push_glob(walk, glob, 1);
 }
 
-static int push_head(git_revwalk *walk, int hide)
-{
-	git_reference *ref, *resolved;
-	int error;
-
-	error = git_reference_lookup(&ref, walk->repo, "HEAD");
-	if (error < GIT_SUCCESS) {
-		return error;
-	}
-	error = git_reference_resolve(&resolved, ref);
-	if (error < GIT_SUCCESS) {
-		return error;
-	}
-	git_reference_free(ref);
-
-	error  = push_commit(walk, git_reference_oid(resolved), hide);
-
-	git_reference_free(resolved);
-	return error;
-}
-
 int git_revwalk_push_head(git_revwalk *walk)
 {
 	assert(walk);
-	return push_head(walk, 0);
+	return push_ref(walk, GIT_HEAD_FILE, 0);
 }
 
 int git_revwalk_hide_head(git_revwalk *walk)
 {
 	assert(walk);
-	return push_head(walk, 1);
+	return push_ref(walk, GIT_HEAD_FILE, 1);
+}
+
+int git_revwalk_push_ref(git_revwalk *walk, const char *refname)
+{
+	assert(walk && refname);
+	return push_ref(walk, refname, 0);
+}
+
+int git_revwalk_hide_ref(git_revwalk *walk, const char *refname)
+{
+	assert(walk && refname);
+	return push_ref(walk, refname, 1);
 }
 
 static int revwalk_enqueue_timesort(git_revwalk *walk, commit_object *commit)

tests-clar/revwalk/basic.c

@@ -148,14 +148,13 @@ void test_revwalk_basic__push_head(void)
 	cl_assert(i == 7);
 }
 
-void test_revwalk_basic__push_head_hide_glob(void)
+void test_revwalk_basic__push_head_hide_ref(void)
 {
 	int i = 0;
 	git_oid oid;
 
 	cl_git_pass(git_revwalk_push_head(_walk));
-	/* This is a hack, as we know this will only match the packed-test branch */
-	cl_git_pass(git_revwalk_hide_glob(_walk, "heads/packed-test*"));
+	cl_git_pass(git_revwalk_hide_ref(_walk, "refs/heads/packed-test"));
 
 	while (git_revwalk_next(&oid, _walk) == GIT_SUCCESS) {
 		i++;