for-each-ref: :short format for refname

Tries to shorten the refname to a non-ambiguous name.

Szeder Gábor noticed that the git bash completion takes a
tremendous amount of time to strip leading components from
heads and tags refs (i.e. refs/heads, refs/tags, ...). He
proposed a new atom called 'refbasename' which removes at
most two leading components from the ref name.

I myself, proposed a more dynamic solution, which strips off
common leading components with the matched pattern.

But the current bash solution and both proposals suffer from
one mayor problem: ambiguous refs.

A ref is ambiguous, if it resolves to more than one full refs.
I.e. given the refs refs/heads/xyzzy and refs/tags/xyzzy. The
(short) ref xyzzy can point to both refs.

( Note: Its irrelevant whether the referenced objects are the
  same or not. )

This proposal solves this by checking for ambiguity of the
shorten ref name.

The shortening is done with the same rules for resolving refs
but in the reverse order. The short name is checked if it
resolves to a different ref.

To continue the above example, the output would be like this:

heads/xyzzy
xyzzy

So, if you want just tags, xyzzy is not ambiguous, because it
will resolve to a tag. If you need the heads you get a also
a non-ambiguous short form of the ref.

To integrate this new format into the bash completion to get
only non-ambiguous refs is beyond the scope of this patch.

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Bert Wesarg
2008-09-05 23:16:23 +02:00
committed by Junio C Hamano
parent 80d12c23de
commit 7d66f21a1b
3 changed files with 173 additions and 7 deletions

View File

@ -262,6 +262,50 @@ for i in "--perl --shell" "-s --python" "--python --tcl" "--tcl --perl"; do
"
done
cat >expected <<\EOF
master
testtag
EOF
test_expect_success 'Check short refname format' '
(git for-each-ref --format="%(refname:short)" refs/heads &&
git for-each-ref --format="%(refname:short)" refs/tags) >actual &&
test_cmp expected actual
'
test_expect_success 'Check for invalid refname format' '
test_must_fail git for-each-ref --format="%(refname:INVALID)"
'
cat >expected <<\EOF
heads/master
master
EOF
test_expect_success 'Check ambiguous head and tag refs' '
git checkout -b newtag &&
echo "Using $datestamp" > one &&
git add one &&
git commit -m "Branch" &&
setdate_and_increment &&
git tag -m "Tagging at $datestamp" master &&
git for-each-ref --format "%(refname:short)" refs/heads/master refs/tags/master >actual &&
test_cmp expected actual
'
cat >expected <<\EOF
heads/ambiguous
ambiguous
EOF
test_expect_success 'Check ambiguous head and tag refs II' '
git checkout master &&
git tag ambiguous testtag^0 &&
git branch ambiguous testtag^0 &&
git for-each-ref --format "%(refname:short)" refs/heads/ambiguous refs/tags/ambiguous >actual &&
test_cmp expected actual
'
test_expect_success 'an unusual tag with an incomplete line' '
git tag -m "bogo" bogo &&