credential: handle invalid arguments earlier

The git-credential command only takes one argument: the
operation to perform. If we don't have one, we complain
immediately. But if we have one that we don't recognize, we
don't notice until after we've read the credential from
stdin. This is likely to confuse a user invoking "git
credential -h", as the program will hang waiting for their
input before showing anything.

Let's detect this case early. Likewise, we never noticed
when there are extra arguments beyond the one we're
expecting. Let's catch this with the same conditional.

Note that we don't need to handle "--help" similarly,
because the git wrapper does this before even calling
cmd_credential().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/credential.c b/builtin/credential.c
index 0412fa00f0c85af6e7d3b4f802d6aeecf0c1ae16..879acfbcda75141d3022e9b285e191977a06ba3d 100644 (file)
--- a/builtin/credential.c
+++ b/builtin/credential.c
@@ -10,9 +10,9 @@ int cmd_credential(int argc, const char **argv, const char *prefix)
        const char *op;
        struct credential c = CREDENTIAL_INIT;
 
-       op = argv[1];
-       if (!op)
+       if (argc != 2 || !strcmp(argv[1], "-h"))
                usage(usage_msg);
+       op = argv[1];
 
        if (credential_read(&c, stdin) < 0)
                die("unable to read credential from stdin");