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>
When we speak protocol v2 in this test, we must pass the object-format
header if the algorithm is not SHA-1. Otherwise, git upload-pack fails
because the hash algorithm doesn't match and not because we've failed to
speak the protocol correctly. Pass the header so that our assertions
test what we're really interested in.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When processing the arguments list for a v2 ls-refs or fetch command, we
loop like this:
while (packet_reader_read(request) != PACKET_READ_FLUSH) {
const char *arg = request->line;
...handle arg...
}
to read and handle packets until we see a flush. The hidden assumption
here is that anything except PACKET_READ_FLUSH will give us valid packet
data to read. But that's not true; PACKET_READ_DELIM or PACKET_READ_EOF
will leave packet->line as NULL, and we'll segfault trying to look at
it.
Instead, we should follow the more careful model demonstrated on the
client side (e.g., in process_capabilities_v2): keep looping as long
as we get normal packets, and then make sure that we broke out of the
loop due to a real flush. That fixes the segfault and correctly
diagnoses any unexpected input from the client.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
