From 798c35fcd8a71a094ca68ac05d81e08c5ac8166d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Wed, 29 May 2013 19:12:42 +0700
Subject: get_sha1: warn about full or short object names that look like refs
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When we get 40 hex digits, we immediately assume it's an SHA-1. This
is the right thing to do because we have no way else to specify an
object. If there is a ref with the same object name, it will be
ignored. Warn the user about this case because the ref with full
object name is likely a mistake, for example

    git checkout -b $empty_var $(git rev-parse something)

advice.object_name_warning is not documented because frankly people
should not be aware about it until they encounter this situation.

While at there, warn about ambiguation with abbreviated SHA-1 too.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t1512-rev-parse-disambiguation.sh | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 't')

diff --git a/t/t1512-rev-parse-disambiguation.sh b/t/t1512-rev-parse-disambiguation.sh
index 6b3d797cea..db228086d3 100755
--- a/t/t1512-rev-parse-disambiguation.sh
+++ b/t/t1512-rev-parse-disambiguation.sh
@@ -261,4 +261,22 @@ test_expect_success 'rev-parse --disambiguate' '
 	test "$(sed -e "s/^\(.........\).*/\1/" actual | sort -u)" = 000000000
 '
 
+test_expect_success 'ambiguous 40-hex ref' '
+	TREE=$(git mktree </dev/null) &&
+	REF=`git rev-parse HEAD` &&
+	VAL=$(git commit-tree $TREE </dev/null) &&
+	git update-ref refs/heads/$REF $VAL &&
+	test `git rev-parse $REF 2>err` = $REF &&
+	grep "refname.*${REF}.*ambiguous" err
+'
+
+test_expect_success 'ambiguous short sha1 ref' '
+	TREE=$(git mktree </dev/null) &&
+	REF=`git rev-parse --short HEAD` &&
+	VAL=$(git commit-tree $TREE </dev/null) &&
+	git update-ref refs/heads/$REF $VAL &&
+	test `git rev-parse $REF 2>err` = $VAL &&
+	grep "refname.*${REF}.*ambiguous" err
+'
+
 test_done
-- 
cgit v1.2.3