[PATCH] tag: add --author option

[Mathias Weber <mweb@gmx.ch>]

The tag command does not support the --author option as the
commit command. This adds the --author option to create
annotated tags with a different author.

Signed-off-by: Mathias Weber <mathew.weber@gmail.com>
---
 builtin/tag.c |   26 +++++++++++++++++++++++---
 1 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/builtin/tag.c b/builtin/tag.c
index fe7e5e5..416fa88 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -309,17 +309,34 @@ struct create_tag_options {
 
 static void create_tag(const unsigned char *object, const char *tag,
 		       struct strbuf *buf, struct create_tag_options *opt,
-		       unsigned char *prev, unsigned char *result)
+		       unsigned char *prev, unsigned char *result,
+		       const char *force_author)
 {
 	enum object_type type;
 	char header_buf[1024];
 	int header_len;
 	char *path = NULL;
+	char *name, *email;
+	const char *author_ident;
 
 	type = sha1_object_info(object, NULL);
 	if (type <= OBJ_NONE)
 	    die(_("bad object type."));
 
+	if (force_author) {
+		const char *lb = strstr(force_author, " <");
+		const char *rb = strchr(force_author, '>');
+
+		if (!lb || !rb)
+			die(_("malformed --author parameter"));
+			name = xstrndup(force_author, lb - force_author);
+			email = xstrndup(lb + 2, rb - (lb + 2));
+
+		author_ident = fmt_ident(name, email, getenv("GIT_AUTHOR_DATE"),
+				IDENT_ERROR_ON_NO_NAME);
+	} else
+		author_ident = git_committer_info(IDENT_ERROR_ON_NO_NAME);
+
 	header_len = snprintf(header_buf, sizeof(header_buf),
 			  "object %s\n"
 			  "type %s\n"
@@ -328,7 +345,7 @@ static void create_tag(const unsigned char *object, const char *tag,
 			  sha1_to_hex(object),
 			  typename(type),
 			  tag,
-			  git_committer_info(IDENT_ERROR_ON_NO_NAME));
+			  author_ident);
 
 	if (header_len > sizeof(header_buf) - 1)
 		die(_("tag header too big."));
@@ -438,6 +455,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		delete = 0, verify = 0;
 	const char *msgfile = NULL, *keyid = NULL;
 	struct msg_arg msg = { 0, STRBUF_INIT };
+	const char *force_author = NULL;
 	struct commit_list *with_commit = NULL;
 	struct option options[] = {
 		OPT_BOOLEAN('l', "list", &list, "list tag names"),
@@ -452,6 +470,8 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 					"annotated tag, needs a message"),
 		OPT_CALLBACK('m', "message", &msg, "message",
 			     "tag message", parse_msg_arg),
+		OPT_STRING(0, "author", &force_author, "author",
+				 "override author for annotated tag"),
 		OPT_FILENAME('F', "file", &msgfile, "read message from file"),
 		OPT_BOOLEAN('s', "sign", &opt.sign, "annotated and GPG-signed tag"),
 		OPT_STRING(0, "cleanup", &cleanup_arg, "mode",
@@ -556,7 +576,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		die(_("Invalid cleanup mode %s"), cleanup_arg);
 
 	if (annotate)
-		create_tag(object, tag, &buf, &opt, prev, object);
+		create_tag(object, tag, &buf, &opt, prev, object, force_author);
 
 	lock = lock_any_ref_for_update(ref.buf, prev, 0);
 	if (!lock)
-- 
1.7.5.4