checkout: implement "-" abbreviation, add docs and tests

diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh
index 2852a0326546f50f0cbefb4d5621c889b52f33c9..04522857abb716b8866e0f5153ec33b3ac780536 100755 (executable)
--- a/t/t5300-pack-object.sh
+++ b/t/t5300-pack-object.sh
@@ -272,7 +272,8 @@ test_expect_success \
 
 test_expect_success \
     'make sure index-pack detects the SHA1 collision' \
-    'test_must_fail git index-pack -o bad.idx test-3.pack'
+    'test_must_fail git index-pack -o bad.idx test-3.pack 2>msg &&
+     grep "SHA1 COLLISION FOUND" msg'
 
 test_expect_success \
     'honor pack.packSizeLimit' \