Make builtin-branch.c handle the git config file

This moves the knowledge about .git/config usage out of refs.c and into
builtin-branch.c instead, which allows git-branch to update HEAD to point
at the moved branch before attempting to update the config file. It also
allows git-branch to exit with an error code if updating the config file
should fail.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-branch.c

@@ -493,6 +493,7 @@ static void rename_branch(const char *oldname, const char *newname, int force)
 {
 	char oldref[PATH_MAX], newref[PATH_MAX], logmsg[PATH_MAX*2 + 100];
 	unsigned char sha1[20];
+	char oldsection[PATH_MAX], newsection[PATH_MAX];
 
 	if (!oldname)
 		die("cannot rename the current branch while not on any.");
@@ -521,6 +522,11 @@ static void rename_branch(const char *oldname, const char *newname, int force)
 	/* no need to pass logmsg here as HEAD didn't really move */
 	if (!strcmp(oldname, head) && create_symref("HEAD", newref, NULL))
 		die("Branch renamed to %s, but HEAD is not updated!", newname);
+
+	snprintf(oldsection, sizeof(oldsection), "branch.%s", oldref + 11);
+	snprintf(newsection, sizeof(newsection), "branch.%s", newref + 11);
+	if (git_config_rename_section(oldsection, newsection) < 0)
+		die("Branch is renamed, but update of config-file failed");
 }
 
 int cmd_branch(int argc, const char **argv, const char *prefix)

refs.c

@@ -828,16 +828,6 @@ int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 		goto rollback;
 	}
 
-	if (!prefixcmp(oldref, "refs/heads/") &&
-			!prefixcmp(newref, "refs/heads/")) {
-		char oldsection[1024], newsection[1024];
-
-		snprintf(oldsection, 1024, "branch.%s", oldref + 11);
-		snprintf(newsection, 1024, "branch.%s", newref + 11);
-		if (git_config_rename_section(oldsection, newsection) < 0)
-			error("unable to update config-file");
-	}
-
 	return 0;
 
  rollback: