Previously, if remote.origin.push was set to ":", git would segfault during
a push operation, due to bad parsing logic in
query_matches_negative_refspec. Per bisect, the bug was introduced in:
c0192df630 (refspec: add support for negative refspecs, 2020-09-30)

We found this issue when rolling out git 2.29 at Dropbox - as several folks
had "push = :" in their configuration. I based my diff off the master
branch, but also confirmed that it patches cleanly onto maint - if the
maintainers would like to also fix the segfault on 2.29

Update since Patch series V1:

 * Handled matching refspec explicitly
 * Added testing for "+:" case
 * Added comment explaining how the two loops work together

It may be wise to add additional testing for a case with a matching refspec
+ negative refspec with expected behavior

Nipunn Koorapati (2):
  negative-refspec: fix segfault on : refspec
  negative-refspec: improve comment on query_matches_negative_refspec

 remote.c                          | 16 +++++++++++++---
 t/t5582-fetch-negative-refspec.sh | 15 +++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)

base-commit: 6d3ef5b467eccd2769f1aa1c555d317d3c8dc707

Submitted-As: https://lore.kernel.org/git/pull.820.v2.git.1608415117.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.820.git.1608398598893.gitgitgadget@gmail.com