make "mktag" a built-in

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -389,7 +389,6 @@ PROGRAMS += $(EXTRA_PROGRAMS)
 PROGRAMS += git-fast-import$X
 PROGRAMS += git-imap-send$X
 PROGRAMS += git-index-pack$X
-PROGRAMS += git-mktag$X
 PROGRAMS += git-pack-redundant$X
 PROGRAMS += git-shell$X
 PROGRAMS += git-show-index$X
@@ -670,6 +669,7 @@ BUILTIN_OBJS += builtin-merge-index.o
 BUILTIN_OBJS += builtin-merge-ours.o
 BUILTIN_OBJS += builtin-merge-recursive.o
 BUILTIN_OBJS += builtin-merge-tree.o
+BUILTIN_OBJS += builtin-mktag.o
 BUILTIN_OBJS += builtin-mktree.o
 BUILTIN_OBJS += builtin-mv.o
 BUILTIN_OBJS += builtin-name-rev.o

builtin-mktag.c

@@ -153,7 +153,7 @@ static int verify_tag(char *buffer, unsigned long size)
 
 #undef PD_FMT
 
-int main(int argc, char **argv)
+int cmd_mktag(int argc, const char **argv, const char *prefix)
 {
 	struct strbuf buf = STRBUF_INIT;
 	unsigned char result_sha1[20];
@@ -161,10 +161,6 @@ int main(int argc, char **argv)
 	if (argc != 1)
 		usage("git mktag < signaturefile");
 
-	git_extract_argv0_path(argv[0]);
-
-	setup_git_directory();
-
 	if (strbuf_read(&buf, 0, 4096) < 0) {
 		die_errno("could not read from stdin");
 	}

builtin.h

@@ -73,6 +73,7 @@ extern int cmd_merge_ours(int argc, const char **argv, const char *prefix);
 extern int cmd_merge_file(int argc, const char **argv, const char *prefix);
 extern int cmd_merge_recursive(int argc, const char **argv, const char *prefix);
 extern int cmd_merge_tree(int argc, const char **argv, const char *prefix);
+extern int cmd_mktag(int argc, const char **argv, const char *prefix);
 extern int cmd_mktree(int argc, const char **argv, const char *prefix);
 extern int cmd_mv(int argc, const char **argv, const char *prefix);
 extern int cmd_name_rev(int argc, const char **argv, const char *prefix);

git.c

@@ -338,6 +338,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 		{ "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 		{ "merge-tree", cmd_merge_tree, RUN_SETUP },
+		{ "mktag", cmd_mktag, RUN_SETUP },
 		{ "mktree", cmd_mktree, RUN_SETUP },
 		{ "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 		{ "name-rev", cmd_name_rev, RUN_SETUP },