Re: [PATCH 1/2] range-diff: fix a crash in parsing git-log output
- From
Taylor Blau <me@ttaylorr.com>
- Date
- Apr 15, 2020, 22:02 UTC
- Message-ID
- <20200415220242.GA45241@syl.local>
- In-Reply-To
- <20200415162326.GG2464307@coredump.intra.peff.net>
Hi Peff,
On Wed, Apr 15, 2020 at 12:23:26PM -0400, Jeff King wrote:
Show 35 quoted lines
> On Wed, Apr 15, 2020 at 08:31:39AM -0700, Junio C Hamano wrote: > > > "Vasil Dimov via GitGitGadget" <gitgitgadget@gmail.com> writes: > > > > > From: Vasil Dimov <vd@FreeBSD.org> > > > > > > `git range-diff` calls `git log` internally and tries to parse its > > > output. But `git log` output can be customized by the user in their > > > git config and for certain configurations either an error will be > > > returned by `git range-diff` or it will crash. > > > > > > To fix this explicitly set the output format of the internally > > > executed `git log` with `--pretty=medium`. Because that cancels > > > `--notes`, add explicitly `--notes` at the end. > > > > Good finding. > > > > Shouldn't we also disable customizations that come from the > > configuration variables like diff.external, diff.<driver>.command? > > If range-diff were a script, I would say it should be using the > "rev-list | diff-tree --stdin" plumbing under the hood, rather than > "log". > > The read_patches() function does let callers pass options to git-log, > but I don't _think_ this is exposed to the user. We only allow a few > --notes options to be passed, and we should be able to apply those to > diff-tree. So converting it to use plumbing might be an option. > > Though I think there is another bug: > > $ git rev-list HEAD | git diff-tree --stdin --pretty=medium --notes > commit 8f3d9f354286745c751374f5f1fcafee6b3f3136 > git: notes.c:1308: format_display_notes: Assertion `display_notes_trees' failed. > Aborted
Nice find. I think that I have a patch addressing this below. Please let me know what you think:
--- >8 ---
Subject: [PATCH] diff-tree.c: load notes machinery with '--notes'
Since its introduction in 7249e91 (revision.c: support --notes command-line option, 2011-03-29), combining '--notes' with '--pretty' causes 'git diff-tree' to fail a runtime assertion:
$ git rev-list HEAD | git diff-tree --stdin --pretty=medium --notes commit 8f3d9f354286745c751374f5f1fcafee6b3f3136 git: notes.c:1308: format_display_notes: Assertion `display_notes_trees' failed. Aborted
This failure is due to diff-tree not calling 'load_display_notes' to initialize the notes machinery.
Ordinarily, this failure isn't triggered, because it requires passing both '--notes' and '--pretty'. Specifically, passing '--pretty' sets 'opt->verbose_header', causing 'show_log()' to eventually call 'format_display_notes()', which expects a non-NULL 'display_note_trees'. Without initializing the notes machinery, 'display_note_trees' remains NULL, and thus triggers an assertion failure. This doesn't occur without '--pretty' since we never call 'format_display_notes()' without it.
Fix this by initializing the notes machinery after parsing our options, and harden this behavior against regression with a test in t4013.
Reported-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> --- builtin/diff-tree.c | 2 ++ t/t4013-diff-various.sh | 1 + 2 files changed, 3 insertions(+)
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c index cb9ea79367..17c1cc8c3c 100644 --- a/builtin/diff-tree.c +++ b/builtin/diff-tree.c @@ -126,6 +126,8 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix) precompose_argv(argc, argv); argc = setup_revisions(argc, argv, opt, &s_r_opt); + if (opt->show_notes) + load_display_notes(&opt->notes_opt); while (--argc > 0) { const char *arg = *++argv; diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh index dde3f11fec..6ae8cfb271 100755 --- a/t/t4013-diff-various.sh +++ b/t/t4013-diff-various.sh @@ -398,6 +398,7 @@ diff --no-index --raw --no-abbrev dir2 dir diff-tree --pretty --root --stat --compact-summary initial diff-tree --pretty -R --root --stat --compact-summary initial +diff-tree --pretty --notes initial diff-tree --stat --compact-summary initial mode diff-tree -R --stat --compact-summary initial mode EOF -- 2.26.0.106.g9fadedd637