git: show alias info only with lone -h

Builtin commands show usage information on stdout if called with -h as
their only option, usage.c::show_usage_if_asked() makes sure of that.

Aliases show alias information on stderr if called with -h as the first
option since a9a60b9 (git.c: handle_alias: prepend alias info when
first argument is -h, 2018-10-09).  This is surprising when using
aliases for commands that take -h as a normal argument among others,
like git grep.

Tighten the condition and show the alias information only if -h is the
only option given, to be consistent with builtins.

It's probably still is a good idea to write to stderr, as an alias
command doesn't have to be a builtin and could instead produce output
with just -h that might be spoiled by an extra alias info line.

Reported-by: Kevin Brodsky <[email protected]>
Signed-off-by: René Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

git.c

@@ -371,7 +371,7 @@ static int handle_alias(struct strvec *args)
 	alias_command = args->v[0];
 	alias_string = alias_lookup(alias_command);
 	if (alias_string) {
-		if (args->nr > 1 && !strcmp(args->v[1], "-h"))
+		if (args->nr == 2 && !strcmp(args->v[1], "-h"))
 			fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
 				   alias_command, alias_string);
 		if (alias_string[0] == '!') {