Re: [Bug?] "git show -s" still worries about renameLimit?
- From
Jeff King <peff@peff.net>
- Date
- May 4, 2025, 08:27 UTC
- Message-ID
- <20250504082715.GA6257@coredump.intra.peff.net>
- In-Reply-To
- <xmqq8qncst4f.fsf@gitster.g>
On Sun, May 04, 2025 at 01:00:16AM -0700, Junio C Hamano wrote:
Show 19 quoted lines
> $ git show -s | cat > warning: exhaustive rename detection was skipped due to too many files. > warning: you may want to set your diff.renameLimit variable to at least 6123 and retry the command. > commit a3a9dd8be6b8767e690b014715aefa2ba39672e2 (HEAD -> master) > Author: Junio C Hamano <gitster@pobox.com> > Date: Sat Apr 19 14:27:03 2025 -0700 > > Something something something > > As we have -M (rename detection) on by default these days, and this > particular commit has very many deletions and creations, if we were > asking to show some diff (not necessarily patch text output, but > just "--stat" or even "--raw") it is fair to warn about rename > detection being limited by diff.renameLimit. > > But the command knows that with "-s" the user declined to show any > diff computation, so it feels wrong to even _count_ how many > diff_filepairs there are and comparing with the renameLimit, in > order to warn about busting the limit.
This seemed eerily familiar. See this thread:
https://lore.kernel.org/git/87h750q1b9.fsf@gnu.org/
and in particular this proposal:
https://lore.kernel.org/git/YqI%2FTcZyXomxtXtN@coredump.intra.peff.net/
I've been carrying that patch in my tree (reproduced below), but I don't remember why I never polished it. I wonder if it was the question about --exit-code below. Or maybe I was just nervous about other corner cases.
-- >8 -- Subject: [PATCH] show: skip diff when possible
Running:
git show -s $commit
will still compute a diff for $commit, even though we aren't going to show it. This is wasted computation, since it cannot affect the output or exit code of the program.
In the more general case:
- if the requested diff format is NO_OUTPUT, then we won't change the
output of the diff itself - if rev_info.always_show_header is set, then we will show the commit
regardless of whether the diff is empty (which is true for git-show,
for example, but not git-log)- we don't use --exit-code here (should check?)
Signed-off-by: Jeff King <peff@peff.net> --- log-tree.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/log-tree.c b/log-tree.c index a4d4ab59ca..740219ce99 100644 --- a/log-tree.c +++ b/log-tree.c @@ -1105,6 +1105,10 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log if (!all_need_diff && !opt->merges_need_diff) return 0; + if (opt->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT && + opt->always_show_header) + return 0; + parse_commit_or_die(commit); oid = get_commit_tree_oid(commit);
-- 2.49.0.754.gd827f9aa09