connect: also update offset for features without values

parse_feature_value() takes an offset, and uses it to seek past the
point in features_list that we've already seen. However if the feature
being searched for does not specify a value, the offset is not
updated. Therefore if we call parse_feature_value() in a loop on a
value-less feature, we'll keep on parsing the same feature over and over
again. This usually isn't an issue: there's no point in using
next_server_feature_value() to search for repeated instances of the same
capability unless that capability typically specifies a value - but a
broken server could send a response that omits the value for a feature
even when we are expecting a value.

Therefore we add an offset update calculation for the no-value case,
which helps ensure that loops using next_server_feature_value() will
always terminate.

next_server_feature_value(), and the offset calculation, were first
added in 2.28 in 2c6a403d96 (connect: add function to parse multiple
v1 capability values, 2020-05-25).

Thanks to Peff for authoring the test.

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Andrzej Hunt <andrzej@ahunt.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Andrzej Hunt 2021-09-26 15:58:33 +00:00 committed by Junio C Hamano
parent 225bc32a98
commit 44d2aec6e8
2 changed files with 17 additions and 0 deletions

View File

@ -555,6 +555,8 @@ const char *parse_feature_value(const char *feature_list, const char *feature, i
if (!*value || isspace(*value)) {
if (lenp)
*lenp = 0;
if (offset)
*offset = found + len - feature_list;
return value;
}
/* feature with a value (e.g., "agent=git/1.2.3") */

View File

@ -32,4 +32,19 @@ test_expect_success 'extra delim packet in v2 fetch args' '
test_i18ngrep "expected flush after fetch arguments" err
'
test_expect_success 'bogus symref in v0 capabilities' '
test_commit foo &&
oid=$(git rev-parse HEAD) &&
dst=refs/heads/foo &&
{
printf "%s HEAD\0symref object-format=%s symref=HEAD:%s\n" \
"$oid" "$GIT_DEFAULT_HASH" "$dst" |
test-tool pkt-line pack-raw-stdin &&
printf "0000"
} >input &&
git ls-remote --symref --upload-pack="cat input; read junk;:" . >actual &&
printf "ref: %s\tHEAD\n%s\tHEAD\n" "$dst" "$oid" >expect &&
test_cmp expect actual
'
test_done