receive-pack: make it a builtin

It is a good thing to do in general, but more importantly, transport
routines can only be used by built-ins, which is what I'll be adding next.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -294,7 +294,6 @@ PROGRAMS += git-mktag$X
 PROGRAMS += git-mktree$X
 PROGRAMS += git-pack-redundant$X
 PROGRAMS += git-patch-id$X
-PROGRAMS += git-receive-pack$X
 PROGRAMS += git-send-pack$X
 PROGRAMS += git-shell$X
 PROGRAMS += git-show-index$X
@@ -546,6 +545,7 @@ BUILTIN_OBJS += builtin-prune-packed.o
 BUILTIN_OBJS += builtin-prune.o
 BUILTIN_OBJS += builtin-push.o
 BUILTIN_OBJS += builtin-read-tree.o
+BUILTIN_OBJS += builtin-receive-pack.o
 BUILTIN_OBJS += builtin-reflog.o
 BUILTIN_OBJS += builtin-remote.o
 BUILTIN_OBJS += builtin-rerere.o

builtin-receive-pack.c

@@ -462,14 +462,14 @@ static int delete_only(struct command *cmd)
 	return 1;
 }
 
-int main(int argc, char **argv)
+int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 {
 	int i;
 	char *dir = NULL;
 
 	argv++;
 	for (i = 1; i < argc; i++) {
-		char *arg = *argv++;
+		const char *arg = *argv++;
 
 		if (*arg == '-') {
 			/* Do flag handling here */
@@ -477,7 +477,7 @@ int main(int argc, char **argv)
 		}
 		if (dir)
 			usage(receive_pack_usage);
-		dir = arg;
+		dir = xstrdup(arg);
 	}
 	if (!dir)
 		usage(receive_pack_usage);

builtin.h

@@ -78,6 +78,7 @@ extern int cmd_prune(int argc, const char **argv, const char *prefix);
 extern int cmd_prune_packed(int argc, const char **argv, const char *prefix);
 extern int cmd_push(int argc, const char **argv, const char *prefix);
 extern int cmd_read_tree(int argc, const char **argv, const char *prefix);
+extern int cmd_receive_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_reflog(int argc, const char **argv, const char *prefix);
 extern int cmd_remote(int argc, const char **argv, const char *prefix);
 extern int cmd_config(int argc, const char **argv, const char *prefix);

git.c

@@ -328,6 +328,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "prune-packed", cmd_prune_packed, RUN_SETUP },
 		{ "push", cmd_push, RUN_SETUP },
 		{ "read-tree", cmd_read_tree, RUN_SETUP },
+		{ "receive-pack", cmd_receive_pack },
 		{ "reflog", cmd_reflog, RUN_SETUP },
 		{ "remote", cmd_remote, RUN_SETUP },
 		{ "repo-config", cmd_config },