[PATCH v5 10/25] get_sha1(): fix error status regression

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 3, 2012, 21:37 UTC
Message-ID: <1341351435-31011-11-git-send-email-gitster@pobox.com>
In-Reply-To: <1341351435-31011-1-git-send-email-gitster@pobox.com>

In finish_object_disambiguation(), if the candidate hasn't been checked, there are two cases:

 - It is the first and only object that match the prefix; or
 - It replaced another object that matched the prefix but that
   object did not satisfy ds->fn() callback.

And the former case we set ds->candidate_ok to true without doing anything else, while for the latter we check the candidate, which may set ds->candidate_ok to false.

At this point in the code, ds->candidate_ok can be false only if this last-round check found that the candidate does not pass the check, because the state after update_candidates() returns cannot satisfy

    !ds->ambiguous && ds->candidate_exists && ds->candidate_checked

and !ds->canidate_ok at the same time.

Hence, when we execute this "return", we know we have seen more than one object that match the prefix (and none of them satisfied ds->fn), meaning that we should say "the short name is ambiguous", not "there is no object that matches the prefix".

Noticed by Jeff King.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sha1_name.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sha1_name.c b/sha1_name.c
index 2e2dbb8..c824bdd 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -212,7 +212,7 @@ static int finish_object_disambiguation(struct disambiguate_state *ds,
 				    ds->fn(ds->candidate, ds->cb_data));
 
 	if (!ds->candidate_ok)
-		return SHORT_NAME_NOT_FOUND;
+		return SHORT_NAME_AMBIGUOUS;
 
 	hashcpy(sha1, ds->candidate);
 	return 0;

-- 
1.7.11.1.229.g706c98f