push: detect local refspec errors earlyjk/detect-push-typo-early

When pushing, we do not even look at our push refspecs until
after we have made contact with the remote receive-pack and
gotten its list of refs. This means that we may go to some
work, including asking the user to log in, before realizing
we have simple errors like "git push origin matser".

We cannot catch all refspec problems, since fully evaluating
the refspecs requires knowing what the remote side has. But
we can do a quick sanity check of the local side and catch a
few simple error cases.

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

1 files changed, 25 insertions, 0 deletions

diff --git a/remote.c b/remote.c
index b6586c089f..9bf498af1b 100644
--- a/remote.c
+++ b/remote.c
@@ -1374,6 +1374,31 @@ static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
 }
 
 /*
+ * Given only the set of local refs, sanity-check the set of push
+ * refspecs. We can't catch all errors that match_push_refs would,
+ * but we can catch some errors early before even talking to the
+ * remote side.
+ */
+int check_push_refs(struct ref *src, int nr_refspec, const char **refspec_names)
+{
+	struct refspec *refspec = parse_push_refspec(nr_refspec, refspec_names);
+	int ret = 0;
+	int i;
+
+	for (i = 0; i < nr_refspec; i++) {
+		struct refspec *rs = refspec + i;
+
+		if (rs->pattern || rs->matching)
+			continue;
+
+		ret |= match_explicit_lhs(src, rs, NULL, NULL);
+	}
+
+	free_refspec(nr_refspec, refspec);
+	return ret;
+}
+
+/*
  * Given the set of refs the local repository has, the set of refs the
  * remote repository has, and the refspec used for push, determine
  * what remote refs we will update and with what value by setting