Merge pull request #1920 from libgit2/cmn/ref-with-log

Reference operations with log

include/git2/reflog.h

@@ -47,7 +47,7 @@ GIT_EXTERN(int) git_reflog_read(git_reflog **out, git_repository *repo,  const c
 GIT_EXTERN(int) git_reflog_write(git_reflog *reflog);
 
 /**
- * Add a new entry to the reflog.
+ * Add a new entry to the in-memory reflog.
  *
  * `msg` is optional and can be NULL.
  *
@@ -60,23 +60,6 @@ GIT_EXTERN(int) git_reflog_write(git_reflog *reflog);
 GIT_EXTERN(int) git_reflog_append(git_reflog *reflog, const git_oid *id, const git_signature *committer, const char *msg);
 
 /**
- * Add a new entry to the named reflog.
- *
- * This utility function loads the named reflog, appends to it and
- * writes it back out to the backend.
- *
- * `msg` is optional and can be NULL.
- *
- * @param repo the repository to act on
- * @param name the reflog's name
- * @param id the OID the reference is now pointing to
- * @param committer the signature of the committer
- * @param msg the reflog message
- * @return 0 or an error code
- */
-GIT_EXTERN(int) git_reflog_append_to(git_repository *repo, const char *name, const git_oid *id, const git_signature *committer, const char *msg);
-
-/**
  * Rename a reflog
  *
  * The reflog to be renamed is expected to already exist

include/git2/refs.h

@@ -99,6 +99,48 @@ GIT_EXTERN(int) git_reference_dwim(git_reference **out, git_repository *repo, co
 GIT_EXTERN(int) git_reference_symbolic_create(git_reference **out, git_repository *repo, const char *name, const char *target, int force);
 
 /**
+ * Create a new symbolic reference and update the reflog with a given
+ * message.
+ *
+ * A symbolic reference is a reference name that refers to another
+ * reference name.  If the other name moves, the symbolic name will move,
+ * too.  As a simple example, the "HEAD" reference might refer to
+ * "refs/heads/master" while on the "master" branch of a repository.
+ *
+ * The symbolic reference will be created in the repository and written to
+ * the disk.  The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param target The target of the reference
+ * @param force Overwrite existing references
+ * @param signature The identity that will used to populate the reflog entry
+ * @param log_message The one line long message that has to be appended
+ * to the reflog
+ * @return 0 on success, EEXISTS, EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_symbolic_create_with_log(
+	git_reference **out,
+	git_repository *repo,
+	const char *name,
+	const char *target,
+	int force,
+	const git_signature *signature,
+	const char *log_message);
+
+/**
  * Create a new direct reference.
  *
  * A direct reference (also called an object id reference) refers directly
@@ -131,6 +173,49 @@ GIT_EXTERN(int) git_reference_symbolic_create(git_reference **out, git_repositor
 GIT_EXTERN(int) git_reference_create(git_reference **out, git_repository *repo, const char *name, const git_oid *id, int force);
 
 /**
+ * Create a new direct reference and update the reflog with a given
+ * message.
+ *
+ * A direct reference (also called an object id reference) refers directly
+ * to a specific object id (a.k.a. OID or SHA) in the repository.  The id
+ * permanently refers to the object (although the reference itself can be
+ * moved).  For example, in libgit2 the direct ref "refs/tags/v0.17.0"
+ * refers to OID 5b9fac39d8a76b9139667c26a63e6b3f204b3977.
+ *
+ * The direct reference will be created in the repository and written to
+ * the disk.  The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param id The object id pointed to by the reference.
+ * @param force Overwrite existing references
+ * @param signature The identity that will used to populate the reflog entry
+ * @param log_message The one line long message that has to be appended
+ * to the reflog
+ * @return 0 on success, EEXISTS, EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_create_with_log(
+	git_reference **out,
+	git_repository *repo,
+	const char *name,
+	const git_oid *id,
+	int force,
+	const git_signature *signature,
+	const char *log_message);
+
+/**
  * Get the OID pointed to by a direct reference.
  *
  * Only available if the reference is direct (i.e. an object id reference,
@@ -234,6 +319,31 @@ GIT_EXTERN(int) git_reference_symbolic_set_target(
 
 /**
  * Create a new reference with the same name as the given reference but a
+ * different symbolic target  and update the reflog with a given message.
+ *
+ * The reference must be a symbolic reference, otherwise this will fail.
+ *
+ * The new reference will be written to disk, overwriting the given reference.
+ *
+ * The target name will be checked for validity.
+ * See `git_reference_create_symbolic()` for rules about valid names.
+ *
+ * @param out Pointer to the newly created reference
+ * @param ref The reference
+ * @param target The new target for the reference
+ * @param signature The identity that will used to populate the reflog entry
+ * @param log_message The one line long message that has to be appended
+ * @return 0 on success, EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_symbolic_set_target_with_log(
+	git_reference **out,
+	git_reference *ref,
+	const char *target,
+	const git_signature *signature,
+	const char *log_message);
+
+/**
+ * Create a new reference with the same name as the given reference but a
  * different OID target. The reference must be a direct reference, otherwise
  * this will fail.
  *
@@ -250,6 +360,29 @@ GIT_EXTERN(int) git_reference_set_target(
 	const git_oid *id);
 
 /**
+ * Create a new reference with the same name as the given reference but a
+ * different OID target and update the reflog with a given message.
+ *
+ * The reference must be a direct reference, otherwise this will fail.
+ *
+ * The new reference will be written to disk, overwriting the given reference.
+ *
+ * @param out Pointer to the newly created reference
+ * @param ref The reference
+ * @param id The new target OID for the reference
+ * @param signature The identity that will used to populate the reflog entry
+ * @param log_message The one line long message that has to be appended
+ * to the reflog
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_reference_set_target_with_log(
+	git_reference **out,
+	git_reference *ref,
+	const git_oid *id,
+	const git_signature *signature,
+	const char *log_message);
+
+/**
  * Rename an existing reference.
  *
  * This method works for both direct and symbolic references.
@@ -428,12 +561,24 @@ GIT_EXTERN(int) git_reference_foreach_glob(
 /**
  * Check if a reflog exists for the specified reference.
  *
- * @param ref A git reference
- *
+ * @param repo the repository
+ * @param refname the reference's name
  * @return 0 when no reflog can be found, 1 when it exists;
  * otherwise an error code.
  */
-GIT_EXTERN(int) git_reference_has_log(git_reference *ref);
+GIT_EXTERN(int) git_reference_has_log(git_repository *repo, const char *refname);
+
+/**
+ * Ensure there is a reflog for a particular reference.
+ *
+ * Make sure that successive updates to the reference will append to
+ * its log.
+ *
+ * @param repo the repository
+ * @param refname the reference's name
+ * @return 0 or an error code.
+ */
+GIT_EXTERN(int) git_reference_ensure_log(git_repository *repo, const char *refname);
 
 /**
  * Check if a reference is a local branch.

include/git2/sys/refdb_backend.h

@@ -93,11 +93,13 @@ struct git_refdb_backend {
 	 * must provide this function.
 	 */
 	int (*write)(git_refdb_backend *backend,
-		const git_reference *ref, int force);
+		     const git_reference *ref, int force,
+		     const git_signature *who, const char *message);
 
 	int (*rename)(
 		git_reference **out, git_refdb_backend *backend,
-		const char *old_name, const char *new_name, int force);
+		const char *old_name, const char *new_name, int force,
+		const git_signature *who, const char *message);
 
 	/**
 	 * Deletes the given reference from the refdb.  A refdb implementation
@@ -115,6 +117,17 @@ struct git_refdb_backend {
 	int (*compress)(git_refdb_backend *backend);
 
 	/**
+	 * Query whether a particular reference has a log (may be empty)
+	 */
+	int (*has_log)(git_refdb_backend *backend, const char *refname);
+
+	/**
+	 * Make sure a particular reference will have a reflog which
+	 * will be appended to on writes.
+	 */
+	int (*ensure_log)(git_refdb_backend *backend, const char *refname);
+
+	/**
 	 * Frees any resources held by the refdb.  A refdb implementation may
 	 * provide this function; if it is not provided, nothing will be done.
 	 */

src/refdb.c

@@ -167,14 +167,14 @@ void git_refdb_iterator_free(git_reference_iterator *iter)
 	iter->free(iter);
 }
 
-int git_refdb_write(git_refdb *db, git_reference *ref, int force)
+int git_refdb_write(git_refdb *db, git_reference *ref, int force, const git_signature *who, const char *message)
 {
 	assert(db && db->backend);
 
 	GIT_REFCOUNT_INC(db);
 	ref->db = db;
 
-	return db->backend->write(db->backend, ref, force);
+	return db->backend->write(db->backend, ref, force, who, message);
 }
 
 int git_refdb_rename(
@@ -182,12 +182,14 @@ int git_refdb_rename(
 	git_refdb *db,
 	const char *old_name,
 	const char *new_name,
-	int force)
+	int force,
+	const git_signature *who,
+	const char *message)
 {
 	int error;
 
 	assert(db && db->backend);
-	error = db->backend->rename(out, db->backend, old_name, new_name, force);
+	error = db->backend->rename(out, db->backend, old_name, new_name, force, who, message);
 	if (error < 0)
 		return error;
 
@@ -219,3 +221,17 @@ int git_refdb_reflog_read(git_reflog **out, git_refdb *db,  const char *name)
 
 	return 0;
 }
+
+int git_refdb_has_log(git_refdb *db, const char *refname)
+{
+	assert(db && refname);
+
+	return db->backend->has_log(db->backend, refname);
+}
+
+int git_refdb_ensure_log(git_refdb *db, const char *refname)
+{
+	assert(db && refname);
+
+	return db->backend->ensure_log(db->backend, refname);
+}

src/refdb.h

@@ -33,18 +33,24 @@ int git_refdb_rename(
 	git_refdb *db,
 	const char *old_name,
 	const char *new_name,
-	int force);
+	int force,
+	const git_signature *who,
+	const char *message);
 
 int git_refdb_iterator(git_reference_iterator **out, git_refdb *db, const char *glob);
 int git_refdb_iterator_next(git_reference **out, git_reference_iterator *iter);
 int git_refdb_iterator_next_name(const char **out, git_reference_iterator *iter);
 void git_refdb_iterator_free(git_reference_iterator *iter);
 
-int git_refdb_write(git_refdb *refdb, git_reference *ref, int force);
+int git_refdb_write(git_refdb *refdb, git_reference *ref, int force, const git_signature *who, const char *message);
 int git_refdb_delete(git_refdb *refdb, const char *ref_name);
 
 int git_refdb_reflog_read(git_reflog **out, git_refdb *db,  const char *name);
 int git_refdb_reflog_write(git_reflog *reflog);
 
+int git_refdb_has_log(git_refdb *db, const char *refname);
+int git_refdb_ensure_log(git_refdb *refdb, const char *refname);
+
+
 
 #endif

src/refdb_fs.c

@@ -688,9 +688,8 @@ static int reference_path_available(
 	return 0;
 }
 
-static int loose_write(refdb_fs_backend *backend, const git_reference *ref)
+static int loose_lock(git_filebuf *file, refdb_fs_backend *backend, const git_reference *ref)
 {
-	git_filebuf file = GIT_FILEBUF_INIT;
 	git_buf ref_path = GIT_BUF_INIT;
 
 	/* Remove a possibly existing empty directory hierarchy
@@ -702,25 +701,29 @@ static int loose_write(refdb_fs_backend *backend, const git_reference *ref)
 	if (git_buf_joinpath(&ref_path, backend->path, ref->name) < 0)
 		return -1;
 
-	if (git_filebuf_open(&file, ref_path.ptr, GIT_FILEBUF_FORCE, GIT_REFS_FILE_MODE) < 0) {
+	if (git_filebuf_open(file, ref_path.ptr, GIT_FILEBUF_FORCE, GIT_REFS_FILE_MODE) < 0) {
 		git_buf_free(&ref_path);
 		return -1;
 	}
 
 	git_buf_free(&ref_path);
+	return 0;
+}
 
+static int loose_commit(git_filebuf *file, const git_reference *ref)
+{
 	if (ref->type == GIT_REF_OID) {
 		char oid[GIT_OID_HEXSZ + 1];
 		git_oid_nfmt(oid, sizeof(oid), &ref->target.oid);
 
-		git_filebuf_printf(&file, "%s\n", oid);
+		git_filebuf_printf(file, "%s\n", oid);
 	} else if (ref->type == GIT_REF_SYMBOLIC) {
-		git_filebuf_printf(&file, GIT_SYMREF "%s\n", ref->target.symbolic);
+		git_filebuf_printf(file, GIT_SYMREF "%s\n", ref->target.symbolic);
 	} else {
 		assert(0); /* don't let this happen */
 	}
 
-	return git_filebuf_commit(&file);
+	return git_filebuf_commit(file);
 }
 
 /*
@@ -907,12 +910,33 @@ fail:
 	return -1;
 }
 
+static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, const git_signature *author, const char *message);
+static int has_reflog(git_repository *repo, const char *name);
+
+/* We only write if it's under heads/, remotes/ or notes/ or if it already has a log */
+static bool should_write_reflog(git_repository *repo, const char *name)
+{
+	if (has_reflog(repo, name))
+		return 1;
+
+	if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR) ||
+	    !git__strcmp(name, GIT_HEAD_FILE) ||
+	    !git__prefixcmp(name, GIT_REFS_REMOTES_DIR) ||
+	    !git__prefixcmp(name, GIT_REFS_NOTES_DIR))
+		return 1;
+
+	return 0;
+}
+
 static int refdb_fs_backend__write(
 	git_refdb_backend *_backend,
 	const git_reference *ref,
-	int force)
+	int force,
+	const git_signature *who,
+	const char *message)
 {
 	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
+	git_filebuf file = GIT_FILEBUF_INIT;
 	int error;
 
 	assert(backend);
@@ -921,7 +945,17 @@ static int refdb_fs_backend__write(
 	if (error < 0)
 		return error;
 
-	return loose_write(backend, ref);
+	/* We need to perform the reflog append under the ref's lock */
+	if ((error = loose_lock(&file, backend, ref)) < 0)
+		return error;
+
+	if (should_write_reflog(backend->repo, ref->name) &&
+	    (error = reflog_append(backend, ref, who, message)) < 0) {
+		git_filebuf_cleanup(&file);
+		return error;
+	}
+
+	return loose_commit(&file, ref);
 }
 
 static int refdb_fs_backend__delete(
@@ -969,15 +1003,20 @@ static int refdb_fs_backend__delete(
 	return packed_write(backend);
 }
 
+static int refdb_reflog_fs__rename(git_refdb_backend *_backend, const char *old_name, const char *new_name);
+
 static int refdb_fs_backend__rename(
 	git_reference **out,
 	git_refdb_backend *_backend,
 	const char *old_name,
 	const char *new_name,
-	int force)
+	int force,
+	const git_signature *who,
+	const char *message)
 {
 	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
 	git_reference *old, *new;
+	git_filebuf file = GIT_FILEBUF_INIT;
 	int error;
 
 	assert(backend);
@@ -998,7 +1037,28 @@ static int refdb_fs_backend__rename(
 		return -1;
 	}
 
-	if ((error = loose_write(backend, new)) < 0 || out == NULL) {
+	if ((error = loose_lock(&file, backend, new)) < 0) {
+		git_reference_free(new);
+		return error;
+	}
+
+	/* Try to rename the refog; it's ok if the old doesn't exist */
+	error = refdb_reflog_fs__rename(_backend, old_name, new_name);
+	if (((error == 0) || (error == GIT_ENOTFOUND)) &&
+	    ((error = reflog_append(backend, new, who, message)) < 0)) {
+		git_reference_free(new);
+		git_filebuf_cleanup(&file);
+		return error;
+	}
+
+	if (error < 0) {
+		git_reference_free(new);
+		git_filebuf_cleanup(&file);
+		return error;
+	}
+
+
+	if ((error = loose_commit(&file, new)) < 0 || out == NULL) {
 		git_reference_free(new);
 		return error;
 	}
@@ -1173,7 +1233,7 @@ static int create_new_reflog_file(const char *filepath)
 		return error;
 
 	if ((fd = p_open(filepath,
-			O_WRONLY | O_CREAT | O_TRUNC,
+			O_WRONLY | O_CREAT,
 			GIT_REFLOG_FILE_MODE)) < 0)
 		return -1;
 
@@ -1185,6 +1245,50 @@ GIT_INLINE(int) retrieve_reflog_path(git_buf *path, git_repository *repo, const
 	return git_buf_join_n(path, '/', 3, repo->path_repository, GIT_REFLOG_DIR, name);
 }
 
+static int refdb_reflog_fs__ensure_log(git_refdb_backend *_backend, const char *name)
+{
+	refdb_fs_backend *backend;
+	git_repository *repo;
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	assert(_backend && name);
+
+	backend = (refdb_fs_backend *) _backend;
+	repo = backend->repo;
+
+	if ((error = retrieve_reflog_path(&path, repo, name)) < 0)
+		return error;
+
+	return create_new_reflog_file(git_buf_cstr(&path));
+}
+
+static int has_reflog(git_repository *repo, const char *name)
+{
+	int ret = 0;
+	git_buf path = GIT_BUF_INIT;
+
+	if (retrieve_reflog_path(&path, repo, name) < 0)
+		goto cleanup;
+
+	ret = git_path_isfile(git_buf_cstr(&path));
+
+cleanup:
+	git_buf_free(&path);
+	return ret;
+}
+
+static int refdb_reflog_fs__has_log(git_refdb_backend *_backend, const char *name)
+{
+	refdb_fs_backend *backend;
+
+	assert(_backend && name);
+
+	backend = (refdb_fs_backend *) _backend;
+
+	return has_reflog(backend->repo, name);
+}
+
 static int refdb_reflog_fs__read(git_reflog **out, git_refdb_backend *_backend, const char *name)
 {
 	int error = -1;
@@ -1264,34 +1368,48 @@ static int serialize_reflog_entry(
 	return git_buf_oom(buf);
 }
 
+static int lock_reflog(git_filebuf *file, refdb_fs_backend *backend, const char *refname)
+{
+	git_repository *repo;
+	git_buf log_path = GIT_BUF_INIT;
+	int error;
+
+	repo = backend->repo;
+
+	if (retrieve_reflog_path(&log_path, repo, refname) < 0)
+		return -1;
+
+	if (!git_path_isfile(git_buf_cstr(&log_path))) {
+		giterr_set(GITERR_INVALID,
+			"Log file for reference '%s' doesn't exist.", refname);
+		error = -1;
+		goto cleanup;
+	}
+
+	error = git_filebuf_open(file, git_buf_cstr(&log_path), 0, GIT_REFLOG_FILE_MODE);
+
+cleanup:
+	git_buf_free(&log_path);
+
+	return error;
+}
+
 static int refdb_reflog_fs__write(git_refdb_backend *_backend, git_reflog *reflog)
 {
 	int error = -1;
 	unsigned int i;
 	git_reflog_entry *entry;
-	git_repository *repo;
 	refdb_fs_backend *backend;
-	git_buf log_path = GIT_BUF_INIT;
 	git_buf log = GIT_BUF_INIT;
 	git_filebuf fbuf = GIT_FILEBUF_INIT;
 
 	assert(_backend && reflog);
 
 	backend = (refdb_fs_backend *) _backend;
-	repo = backend->repo;
 
-	if (retrieve_reflog_path(&log_path, repo, reflog->ref_name) < 0)
+	if ((error = lock_reflog(&fbuf, backend, reflog->ref_name)) < 0)
 		return -1;
 
-	if (!git_path_isfile(git_buf_cstr(&log_path))) {
-		giterr_set(GITERR_INVALID,
-			"Log file for reference '%s' doesn't exist.", reflog->ref_name);
-		goto cleanup;
-	}
-
-	if ((error = git_filebuf_open(&fbuf, git_buf_cstr(&log_path), 0, GIT_REFLOG_FILE_MODE)) < 0)
-		goto cleanup;
-
 	git_vector_foreach(&reflog->entries, i, entry) {
 		if (serialize_reflog_entry(&log, &(entry->oid_old), &(entry->oid_cur), entry->committer, entry->msg) < 0)
 			goto cleanup;
@@ -1308,7 +1426,49 @@ cleanup:
 
 success:
 	git_buf_free(&log);
-	git_buf_free(&log_path);
+
+	return error;
+}
+
+/* Append to the reflog, must be called under reference lock */
+static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, const git_signature *who, const char *message)
+{
+	int error;
+	git_oid old_id, new_id;
+	git_buf buf = GIT_BUF_INIT, path = GIT_BUF_INIT;
+	git_repository *repo = backend->repo;
+
+	/* Creation of symbolic references doesn't get a reflog entry */
+	if (ref->type == GIT_REF_SYMBOLIC)
+		return 0;
+
+	error = git_reference_name_to_id(&old_id, repo, ref->name);
+	if (error == GIT_ENOTFOUND) {
+		memset(&old_id, 0, sizeof(git_oid));
+		error = 0;
+	}
+	if (error < 0)
+		return error;
+
+	git_oid_cpy(&new_id, git_reference_target(ref));
+
+	if ((error = serialize_reflog_entry(&buf, &old_id, &new_id, who, message)) < 0)
+		goto cleanup;
+
+	if ((error = retrieve_reflog_path(&path, repo, ref->name)) < 0)
+		goto cleanup;
+
+	if (((error = git_futils_mkpath2file(git_buf_cstr(&path), 0777)) < 0) &&
+	    (error != GIT_EEXISTS)) {
+		goto cleanup;
+	}
+
+	error = git_futils_writebuffer(&buf, git_buf_cstr(&path), O_WRONLY|O_CREAT|O_APPEND, GIT_REFLOG_FILE_MODE);
+
+cleanup:
+	git_buf_free(&buf);
+	git_buf_free(&path);
+
 	return error;
 }
 
@@ -1340,6 +1500,11 @@ static int refdb_reflog_fs__rename(git_refdb_backend *_backend, const char *old_
 	if (git_buf_joinpath(&new_path, git_buf_cstr(&temp_path), git_buf_cstr(&normalized)) < 0)
 		return -1;
 
+	if (!git_path_exists(git_buf_cstr(&old_path))) {
+		error = GIT_ENOTFOUND;
+		goto cleanup;
+	}
+
 	/*
 	 * Move the reflog to a temporary place. This two-phase renaming is required
 	 * in order to cope with funny renaming use cases when one tries to move a reference
@@ -1454,6 +1619,8 @@ int git_refdb_backend_fs(
 	backend->parent.del = &refdb_fs_backend__delete;
 	backend->parent.rename = &refdb_fs_backend__rename;
 	backend->parent.compress = &refdb_fs_backend__compress;
+	backend->parent.has_log = &refdb_reflog_fs__has_log;
+	backend->parent.ensure_log = &refdb_reflog_fs__ensure_log;
 	backend->parent.free = &refdb_fs_backend__free;
 	backend->parent.reflog_read = &refdb_reflog_fs__read;
 	backend->parent.reflog_write = &refdb_reflog_fs__write;

src/reflog.c

@@ -230,22 +230,3 @@ int git_reflog_drop(git_reflog *reflog, size_t idx, int rewrite_previous_entry)
 
 	return 0;
 }
-
-int git_reflog_append_to(git_repository *repo, const char *name, const git_oid *id,
-			 const git_signature *committer, const char *msg)
-{
-	int error;
-	git_reflog *reflog;
-
-	if ((error = git_reflog_read(&reflog, repo, name)) < 0)
-		return error;
-
-	if ((error = git_reflog_append(reflog, id, committer, msg)) < 0)
-		goto cleanup;
-
-	error = git_reflog_write(reflog);
-
-cleanup:
-	git_reflog_free(reflog);
-	return error;
-}

src/refs.c

@@ -21,6 +21,7 @@
 #include <git2/refs.h>
 #include <git2/refdb.h>
 #include <git2/sys/refs.h>
+#include <git2/signature.h>
 
 GIT__USE_STRMAP;
 
@@ -328,13 +329,18 @@ static int reference__create(
 	const char *name,
 	const git_oid *oid,
 	const char *symbolic,
-	int force)
+	int force,
+	const git_signature *signature,
+	const char *log_message)
 {
 	char normalized[GIT_REFNAME_MAX];
 	git_refdb *refdb;
 	git_reference *ref = NULL;
 	int error = 0;
 
+	assert(repo && name);
+	assert(symbolic || signature);
+
 	if (ref_out)
 		*ref_out = NULL;
 
@@ -347,15 +353,34 @@ static int reference__create(
 		return error;
 
 	if (oid != NULL) {
+		git_odb *odb;
+
 		assert(symbolic == NULL);
-		ref = git_reference__alloc(normalized, oid, NULL);
+
+		/* Sanity check the reference being created - target must exist. */
+		if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
+			return error;
+
+		if (!git_odb_exists(odb, oid)) {
+			giterr_set(GITERR_REFERENCE,
+				"Target OID for the reference doesn't exist on the repository");
+			return -1;
+		}
+
+		ref = git_reference__alloc(name, oid, NULL);
 	} else {
-		ref = git_reference__alloc_symbolic(normalized, symbolic);
+		char normalized_target[GIT_REFNAME_MAX];
+
+		if ((error = git_reference__normalize_name_lax(
+			normalized_target, sizeof(normalized_target), symbolic)) < 0)
+			return error;
+
+		ref = git_reference__alloc_symbolic(name, normalized_target);
 	}
 
 	GITERR_CHECK_ALLOC(ref);
 
-	if ((error = git_refdb_write(refdb, ref, force)) < 0) {
+	if ((error = git_refdb_write(refdb, ref, force, signature, log_message)) < 0) {
 		git_reference_free(ref);
 		return error;
 	}
@@ -375,22 +400,37 @@ int git_reference_create(
 	const git_oid *oid,
 	int force)
 {
-	git_odb *odb;
-	int error = 0;
+	git_signature *who;
+	int error;
 
-	assert(repo && name && oid);
+	assert(oid);
 
-	/* Sanity check the reference being created - target must exist. */
-	if ((error = git_repository_odb__weakptr(&odb, repo)) < 0)
+	/* Should we return an error if there is no default? */
+	if (((error = git_signature_default(&who, repo)) < 0) &&
+	    ((error = git_signature_now(&who, "unknown", "unknown")) < 0)) {
 		return error;
-
-	if (!git_odb_exists(odb, oid)) {
-		giterr_set(GITERR_REFERENCE,
-			"Target OID for the reference doesn't exist on the repository");
-		return -1;
 	}
 
-	return reference__create(ref_out, repo, name, oid, NULL, force);
+	error = reference__create(ref_out, repo, name, oid, NULL, force, who, NULL);
+
+	git_signature_free(who);
+
+	return error;
+}
+
+int git_reference_create_with_log(
+	git_reference **ref_out,
+	git_repository *repo,
+	const char *name,
+	const git_oid *oid,
+	int force,
+	const git_signature *signature,
+	const char *log_message)
+{
+	assert(oid && signature && log_message);
+
+	return reference__create(
+		ref_out, repo, name, oid, NULL, force, signature, log_message);
 }
 
 int git_reference_symbolic_create(
@@ -400,16 +440,17 @@ int git_reference_symbolic_create(
 	const char *target,
 	int force)
 {
-	char normalized[GIT_REFNAME_MAX];
-	int error = 0;
-
-	assert(repo && name && target);
+	assert(target);
+	return reference__create(ref_out, repo, name, NULL, target, force, NULL, NULL);
+}
 
-	if ((error = git_reference__normalize_name_lax(
-		normalized, sizeof(normalized), target)) < 0)
-		return error;
+static int ensure_is_an_updatable_direct_reference(git_reference *ref)
+{
+	if (ref->type == GIT_REF_OID)
+		return 0;
 
-	return reference__create(ref_out, repo, name, NULL, normalized, force);
+	giterr_set(GITERR_REFERENCE, "Cannot set OID on symbolic reference");
+	return -1;
 }
 
 int git_reference_set_target(
@@ -417,43 +458,68 @@ int git_reference_set_target(
 	git_reference *ref,
 	const git_oid *id)
 {
+	int error;
+
 	assert(out && ref && id);
 
-	if (ref->type != GIT_REF_OID) {
-		giterr_set(GITERR_REFERENCE, "Cannot set OID on symbolic reference");
-		return -1;
-	}
+	if ((error = ensure_is_an_updatable_direct_reference(ref)) < 0)
+		return error;
 
 	return git_reference_create(out, ref->db->repo, ref->name, id, 1);
 }
 
+int git_reference_set_target_with_log(
+	git_reference **out,
+	git_reference *ref,
+	const git_oid *id,
+	const git_signature *signature,
+	const char *log_message)
+{
+	int error;
+
+	assert(out && ref && id);
+	assert(signature && log_message);
+
+	if ((error = ensure_is_an_updatable_direct_reference(ref)) < 0)
+		return error;
+
+	return git_reference_create_with_log(
+		out, ref->db->repo, ref->name, id, 1, signature, log_message);
+}
+
+static int ensure_is_an_updatable_symbolic_reference(git_reference *ref)
+{
+	if (ref->type == GIT_REF_SYMBOLIC)
+		return 0;
+
+	giterr_set(GITERR_REFERENCE, "Cannot set symbolic target on a direct reference");
+	return -1;
+}
+
 int git_reference_symbolic_set_target(
 	git_reference **out,
 	git_reference *ref,
 	const char *target)
 {
+	int error;
+
 	assert(out && ref && target);
 
-	if (ref->type != GIT_REF_SYMBOLIC) {
-		giterr_set(GITERR_REFERENCE,
-			"Cannot set symbolic target on a direct reference");
-		return -1;
-	}
+	if ((error = ensure_is_an_updatable_symbolic_reference(ref)) < 0)
+		return error;
 
 	return git_reference_symbolic_create(out, ref->db->repo, ref->name, target, 1);
 }
 
-int git_reference_rename(
-	git_reference **out,
-	git_reference *ref,
-	const char *new_name,
-	int force)
+static int reference__rename(git_reference **out, git_reference *ref, const char *new_name, int force,
+				 const git_signature *signature, const char *message)
 {
 	unsigned int normalization_flags;
 	char normalized[GIT_REFNAME_MAX];
 	bool should_head_be_updated = false;
 	int error = 0;
-	int reference_has_log;
+
+	assert(ref && new_name && signature);
 
 	normalization_flags = ref->type == GIT_REF_SYMBOLIC ?
 		GIT_REF_FORMAT_ALLOW_ONELEVEL : GIT_REF_FORMAT_NORMAL;
@@ -462,13 +528,14 @@ int git_reference_rename(
 			normalized, sizeof(normalized), new_name, normalization_flags)) < 0)
 		return error;
 
+
 	/* Check if we have to update HEAD. */
 	if ((error = git_branch_is_head(ref)) < 0)
 		return error;
 
 	should_head_be_updated = (error > 0);
 
-	if ((error = git_refdb_rename(out, ref->db, ref->name, new_name, force)) < 0)
+	if ((error = git_refdb_rename(out, ref->db, ref->name, new_name, force, signature, message)) < 0)
 		return error;
 
 	/* Update HEAD it was pointing to the reference being renamed */
@@ -478,15 +545,41 @@ int git_reference_rename(
 		return error;
 	}
 
-	/* Rename the reflog file, if it exists. */
-	reference_has_log = git_reference_has_log(ref);
-	if (reference_has_log < 0)
-		return reference_has_log;
+	return 0;
+}
 
-	if (reference_has_log && (error = git_reflog_rename(git_reference_owner(ref), git_reference_name(ref), new_name)) < 0)
+
+int git_reference_rename(
+	git_reference **out,
+	git_reference *ref,
+	const char *new_name,
+	int force)
+{
+	git_signature *who;
+	int error;
+
+	/* Should we return an error if there is no default? */
+	if (((error = git_signature_default(&who, ref->db->repo)) < 0) &&
+	    ((error = git_signature_now(&who, "unknown", "unknown")) < 0)) {
 		return error;
+	}
 
-	return 0;
+	error = reference__rename(out, ref, new_name, force, who, NULL);
+
+	git_signature_free(who);
+
+	return error;
+}
+
+int git_reference_rename_with_log(
+	git_reference **out,
+	git_reference *ref,
+	const char *new_name,
+	int force,
+	const git_signature *who,
+	const char * message)
+{
+	return reference__rename(out, ref, new_name, force, who, message);
 }
 
 int git_reference_resolve(git_reference **ref_out, const git_reference *ref)
@@ -956,22 +1049,30 @@ int git_reference__update_terminal(
 	return reference__update_terminal(repo, ref_name, oid, 0);
 }
 
-int git_reference_has_log(
-	git_reference *ref)
+int git_reference_has_log(git_repository *repo, const char *refname)
 {
-	git_buf path = GIT_BUF_INIT;
-	int result;
+	int error;
+	git_refdb *refdb;
 
-	assert(ref);
+	assert(repo && refname);
 
-	if (git_buf_join_n(&path, '/', 3, ref->db->repo->path_repository,
-		GIT_REFLOG_DIR, ref->name) < 0)
-		return -1;
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return error;
+
+	return git_refdb_has_log(refdb, refname);
+}
 
-	result = git_path_isfile(git_buf_cstr(&path));
-	git_buf_free(&path);
+int git_reference_ensure_log(git_repository *repo, const char *refname)
+{
+	int error;
+	git_refdb *refdb;
+
+	assert(repo && refname);
+
+	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
+		return error;
 
-	return result;
+	return git_refdb_ensure_log(refdb, refname);
 }
 
 int git_reference__is_branch(const char *ref_name)

src/refs.h

@@ -19,6 +19,7 @@
 #define GIT_REFS_HEADS_DIR GIT_REFS_DIR "heads/"
 #define GIT_REFS_TAGS_DIR GIT_REFS_DIR "tags/"
 #define GIT_REFS_REMOTES_DIR GIT_REFS_DIR "remotes/"
+#define GIT_REFS_NOTES_DIR GIT_REFS_DIR "notes/"
 #define GIT_REFS_DIR_MODE 0777
 #define GIT_REFS_FILE_MODE 0666
 

src/stash.c

@@ -412,25 +412,15 @@ static int update_reflog(
 	const char *message)
 {
 	git_reference *stash;
-	git_reflog *reflog = NULL;
 	int error;
 
-	if ((error = git_reference_create(&stash, repo, GIT_REFS_STASH_FILE, w_commit_oid, 1)) < 0)
-		goto cleanup;
-
-	git_reference_free(stash);
-
-	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE) < 0))
-		goto cleanup;
+	if ((error = git_reference_ensure_log(repo, GIT_REFS_STASH_FILE)) < 0)
+		return error;
 
-	if ((error = git_reflog_append(reflog, w_commit_oid, stasher, message)) < 0)
-		goto cleanup;
+	error = git_reference_create_with_log(&stash, repo, GIT_REFS_STASH_FILE, w_commit_oid, 1, stasher, message);
 
-	if ((error = git_reflog_write(reflog)) < 0)
-		goto cleanup;
+	git_reference_free(stash);
 
-cleanup:
-	git_reflog_free(reflog);
 	return error;
 }
 
@@ -638,7 +628,11 @@ int git_stash_drop(
 		entry = git_reflog_entry_byindex(reflog, 0);
 
 		git_reference_free(stash);
-		error = git_reference_create(&stash, repo, GIT_REFS_STASH_FILE, &entry->oid_cur, 1);
+		if ((error = git_reference_create(&stash, repo, GIT_REFS_STASH_FILE, &entry->oid_cur, 1) < 0))
+			goto cleanup;
+
+		/* We need to undo the writing that we just did */
+		error = git_reflog_write(reflog);
 	}
 
 cleanup:

tests/refs/createwithlog.c

+#include "clar_libgit2.h"
+
+#include "repository.h"
+#include "git2/reflog.h"
+#include "reflog.h"
+#include "ref_helpers.h"
+
+static const char *current_master_tip = "a65fedf39aefe402d3bb6e24df4d4f5fe4547750";
+
+static git_repository *g_repo;
+
+void test_refs_createwithlog__initialize(void)
+{
+   g_repo = cl_git_sandbox_init("testrepo.git");
+}
+
+void test_refs_createwithlog__cleanup(void)
+{
+   cl_git_sandbox_cleanup();
+}
+
+void test_refs_createwithlog__creating_a_direct_reference_adds_a_reflog_entry(void)
+{
+	git_reference *reference;
+	git_oid id;
+	git_signature *signature;
+	git_reflog *reflog;
+	const git_reflog_entry *entry;
+
+	const char *name = "refs/heads/new-head";
+	const char *message = "You've been logged, mate!";
+
+	git_oid_fromstr(&id, current_master_tip);
+
+	cl_git_pass(git_signature_now(&signature, "foo", "foo@bar"));
+
+	cl_git_pass(
+		git_reference_create_with_log(&reference, g_repo, name, &id, 0, signature, message));
+
+	cl_git_pass(git_reflog_read(&reflog, g_repo, name));
+	cl_assert_equal_sz(1, git_reflog_entrycount(reflog));
+
+	entry = git_reflog_entry_byindex(reflog, 0);
+	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) == 0);
+	cl_assert(git_oid_cmp(&id, &entry->oid_cur) == 0);
+	cl_assert_equal_s(message, entry->msg);
+
+	git_reflog_free(reflog);
+	git_reference_free(reference);
+	git_signature_free(signature);
+}

tests/refs/reflog/reflog.c

@@ -49,17 +49,20 @@ static void assert_appends(const git_signature *committer, const git_oid *oid)
 
 	/* Read and parse the reflog for this branch */
 	cl_git_pass(git_reflog_read(&reflog, repo2, new_ref));
-	cl_assert_equal_i(2, (int)git_reflog_entrycount(reflog));
+	cl_assert_equal_i(3, (int)git_reflog_entrycount(reflog));
+
+	/* The first one was the creation of the branch */
+	entry = git_reflog_entry_byindex(reflog, 2);
+	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) == 0);
 
 	entry = git_reflog_entry_byindex(reflog, 1);
 	assert_signature(committer, entry->committer);
-	cl_assert(git_oid_streq(&entry->oid_old, GIT_OID_HEX_ZERO) == 0);
+	cl_assert(git_oid_cmp(oid, &entry->oid_old) == 0);
 	cl_assert(git_oid_cmp(oid, &entry->oid_cur) == 0);
 	cl_assert(entry->msg == NULL);
 
 	entry = git_reflog_entry_byindex(reflog, 0);
 	assert_signature(committer, entry->committer);
-	cl_assert(git_oid_cmp(oid, &entry->oid_old) == 0);
 	cl_assert(git_oid_cmp(oid, &entry->oid_cur) == 0);
 	cl_assert_equal_s(commit_msg, entry->msg);
 
@@ -97,29 +100,6 @@ void test_refs_reflog_reflog__append_then_read(void)
 	git_signature_free(committer);
 }
 
-void test_refs_reflog_reflog__append_to_then_read(void)
-{
-	/* write a reflog for a given reference and ensure it can be read back */
-	git_reference *ref;
-	git_oid oid;
-	git_signature *committer;
-
-	/* Create a new branch pointing at the HEAD */
-	git_oid_fromstr(&oid, current_master_tip);
-	cl_git_pass(git_reference_create(&ref, g_repo, new_ref, &oid, 0));
-	git_reference_free(ref);
-
-	cl_git_pass(git_signature_now(&committer, "foo", "foo@bar"));
-
-	cl_git_fail(git_reflog_append_to(g_repo, new_ref, &oid, committer, "no inner\nnewline"));
-	cl_git_pass(git_reflog_append_to(g_repo, new_ref, &oid, committer, NULL));
-	cl_git_pass(git_reflog_append_to(g_repo, new_ref, &oid, committer, commit_msg "\n"));
-
-	assert_appends(committer, &oid);
-
-	git_signature_free(committer);
-}
-
 void test_refs_reflog_reflog__renaming_the_reference_moves_the_reflog(void)
 {
 	git_reference *master, *new_master;
@@ -147,13 +127,7 @@ void test_refs_reflog_reflog__renaming_the_reference_moves_the_reflog(void)
 
 static void assert_has_reflog(bool expected_result, const char *name)
 {
-	git_reference *ref;
-
-	cl_git_pass(git_reference_lookup(&ref, g_repo, name));
-
-	cl_assert_equal_i(expected_result, git_reference_has_log(ref));
-
-	git_reference_free(ref);
+	cl_assert_equal_i(expected_result, git_reference_has_log(g_repo, name));
 }
 
 void test_refs_reflog_reflog__reference_has_reflog(void)
@@ -207,3 +181,36 @@ void test_refs_reflog_reflog__renaming_with_an_invalid_name_returns_EINVALIDSPEC
 	cl_assert_equal_i(GIT_EINVALIDSPEC,
 			  git_reflog_rename(g_repo, "refs/heads/master", "refs/heads/Inv@{id"));
 }
+
+void test_refs_reflog_reflog__write_only_std_locations(void)
+{
+	git_reference *ref;
+	git_oid id;
+
+	git_oid_fromstr(&id, current_master_tip);
+
+	cl_git_pass(git_reference_create(&ref, g_repo, "refs/heads/foo", &id, 1));
+	git_reference_free(ref);
+	cl_git_pass(git_reference_create(&ref, g_repo, "refs/tags/foo", &id, 1));
+	git_reference_free(ref);
+	cl_git_pass(git_reference_create(&ref, g_repo, "refs/notes/foo", &id, 1));
+	git_reference_free(ref);
+
+	assert_has_reflog(true, "refs/heads/foo");
+	assert_has_reflog(false, "refs/tags/foo");
+	assert_has_reflog(true, "refs/notes/foo");
+
+}
+
+void test_refs_reflog_reflog__write_when_explicitly_active(void)
+{
+	git_reference *ref;
+	git_oid id;
+
+	git_oid_fromstr(&id, current_master_tip);
+	git_reference_ensure_log(g_repo, "refs/tags/foo");
+
+	cl_git_pass(git_reference_create(&ref, g_repo, "refs/tags/foo", &id, 1));
+	git_reference_free(ref);
+	assert_has_reflog(true, "refs/tags/foo");
+}

tests/refs/settargetwithlog.c

+#include "clar_libgit2.h"
+
+#include "repository.h"
+#include "git2/reflog.h"
+#include "reflog.h"
+#include "ref_helpers.h"
+
+static const char *br2_tip = "a4a7dce85cf63874e984719f4fdd239f5145052f";
+static const char *master_tip = "a65fedf39aefe402d3bb6e24df4d4f5fe4547750";
+static const char *br2_name = "refs/heads/br2";
+
+static git_repository *g_repo;
+
+void test_refs_settargetwithlog__initialize(void)
+{
+   g_repo = cl_git_sandbox_init("testrepo.git");
+}
+
+void test_refs_settargetwithlog__cleanup(void)
+{
+   cl_git_sandbox_cleanup();
+}
+
+void test_refs_settargetwithlog__updating_a_direct_reference_adds_a_reflog_entry(void)
+{
+	git_reference *reference, *reference_out;
+	git_oid current_id, target_id;
+	git_signature *signature;
+	git_reflog *reflog;
+	const git_reflog_entry *entry;
+
+	const char *message = "You've been logged, mate!";
+
+	git_oid_fromstr(&current_id, br2_tip);
+	git_oid_fromstr(&target_id, master_tip);
+
+	cl_git_pass(git_reference_lookup(&reference, g_repo, br2_name));
+
+	cl_git_pass(git_signature_now(&signature, "foo", "foo@bar"));
+
+	cl_git_pass(git_reference_set_target_with_log(
+		&reference_out, reference, &target_id, signature, message));
+
+	cl_git_pass(git_reflog_read(&reflog, g_repo, br2_name));
+
+	entry = git_reflog_entry_byindex(reflog, 0);
+	cl_assert(git_oid_cmp(&current_id, &entry->oid_old) == 0);
+	cl_assert(git_oid_cmp(&target_id, &entry->oid_cur) == 0);
+	cl_assert_equal_s(message, entry->msg);
+
+	git_reflog_free(reflog);
+	git_reference_free(reference_out);
+	git_reference_free(reference);
+	git_signature_free(signature);
+}