From: Patrick Steinhardt <ps@pks.im>
To: Jeff King <peff@peff.net>
Cc: git@vger.kernel.org, Junio C Hamano <gitster@pobox.com>,
Felipe Contreras <felipe.contreras@gmail.com>,
Glen Choo <chooglen@google.com>,
Jonathan Tan <jonathantanmy@google.com>,
Jacob Keller <jacob.e.keller@intel.com>
Subject: Re: [PATCH v5 4/9] fetch: print left-hand side when fetching HEAD:foo
Date: Mon, 15 May 2023 07:15:39 +0200 [thread overview]
Message-ID: <ZGG_-7eD9TDanpjP@ncase> (raw)
In-Reply-To: <20230513165925.GA113985@coredump.intra.peff.net>
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On Sat, May 13, 2023 at 12:59:25PM -0400, Jeff King wrote:
> On Wed, May 10, 2023 at 02:34:15PM +0200, Patrick Steinhardt wrote:
>
> > @@ -946,7 +948,7 @@ static int update_local_ref(struct ref *ref,
> > if (oideq(&ref->old_oid, &ref->new_oid)) {
> > if (verbosity > 0)
> > display_ref_update(display_state, '=', _("[up to date]"), NULL,
> > - remote, ref->name, summary_width);
> > + remote_ref->name, ref->name, summary_width);
> > return 0;
> > }
>
> Here (and in other hunks) we now dereference remote_ref unconditionally.
> But in existing parts of the code, we guard against remote_ref being
> NULL. E.g., later on:
>
> if (!current || !updated) {
> const char *msg;
> const char *what;
> int r;
> /*
> * Nicely describe the new ref we're fetching.
> * Base this on the remote's ref name, as it's
> * more likely to follow a standard layout.
> */
> const char *name = remote_ref ? remote_ref->name : "";
> [...]
>
> I'm not sure if the old code was being overly defensive, or if the new
> code is ripe for a segfault. But it's probably worth looking into (it
> was noticed by Coverity).
>
> Looking at the caller, it is always store_update_refs() which passes its
> own "rm", a pointer iterating over ref_map. And it should always be
> non-NULL, since that's the loop condition.
>
> So I think your code is fine, but you might want to double-check my
> logic. (And it may be worth cleaning up the existing redundant check to
> prevent confusion).
I really think that the code is overly defensive. As you mention, there
is a single caller of `update_local_ref()`, only, and that caller
already dereferences the remote reference unconditionally anyway. So if
there was any way for `rm` to become `NULL` we'd already have a segfault
earlier than in `update_local_ref()`.
I'll send a follow-up patch series after the dust has settled that
removes the check.
Thanks!
Patrick
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next prev parent reply other threads:[~2023-05-15 5:15 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-19 12:31 [PATCH 0/8] fetch: introduce machine-parseable output Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 1/8] fetch: split out tests for output format Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 2/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 3/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-04-26 19:20 ` Jacob Keller
2023-04-27 10:58 ` Patrick Steinhardt
2023-04-26 19:21 ` Jacob Keller
2023-04-27 10:58 ` Patrick Steinhardt
2023-04-26 19:25 ` Glen Choo
2023-04-27 10:58 ` Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 4/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 5/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 6/8] fetch: move option related variables " Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 7/8] fetch: introduce new `--output-format` option Patrick Steinhardt
2023-04-26 19:40 ` Glen Choo
2023-04-27 10:58 ` Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-04-26 19:52 ` Glen Choo
2023-04-27 10:58 ` Patrick Steinhardt
2023-04-27 23:20 ` Glen Choo
2023-04-28 8:51 ` Patrick Steinhardt
2023-04-28 17:20 ` Glen Choo
2023-05-02 20:55 ` Felipe Contreras
2023-04-24 20:17 ` [PATCH 0/8] fetch: introduce machine-parseable output Felipe Contreras
2023-04-25 9:58 ` Patrick Steinhardt
2023-04-26 19:14 ` Jacob Keller
2023-04-26 20:23 ` Junio C Hamano
2023-04-26 20:30 ` Jacob Keller
2023-04-27 10:58 ` Patrick Steinhardt
2023-04-27 19:46 ` Jacob Keller
2023-04-27 22:49 ` Glen Choo
2023-04-26 20:24 ` Junio C Hamano
2023-04-26 18:54 ` Glen Choo
2023-04-26 21:14 ` Glen Choo
2023-04-26 19:17 ` Jacob Keller
2023-04-27 11:13 ` [PATCH v2 " Patrick Steinhardt
2023-04-27 11:13 ` [PATCH v2 1/8] fetch: split out tests for output format Patrick Steinhardt
2023-04-29 17:34 ` SZEDER Gábor
2023-05-03 11:21 ` Patrick Steinhardt
2023-04-27 11:13 ` [PATCH v2 2/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-04-27 11:13 ` [PATCH v2 3/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-04-27 17:26 ` Glen Choo
2023-04-27 19:49 ` Jacob Keller
2023-04-27 11:13 ` [PATCH v2 4/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-04-27 11:13 ` [PATCH v2 5/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-04-27 11:13 ` [PATCH v2 6/8] fetch: move option related variables " Patrick Steinhardt
2023-04-27 21:52 ` Junio C Hamano
2023-04-27 11:13 ` [PATCH v2 7/8] fetch: introduce new `--output-format` option Patrick Steinhardt
2023-04-27 22:01 ` Junio C Hamano
2023-04-28 22:03 ` Glen Choo
2023-05-03 9:12 ` Patrick Steinhardt
2023-04-28 22:31 ` Glen Choo
2023-05-03 9:43 ` Patrick Steinhardt
2023-05-03 11:36 ` Patrick Steinhardt
2023-04-27 11:13 ` [PATCH v2 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-04-27 19:52 ` Jacob Keller
2023-04-28 22:42 ` Glen Choo
2023-05-03 11:34 ` [PATCH v3 0/8] fetch: introduce machine-parseable output Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 1/8] fetch: fix `--no-recurse-submodules` with multi-remote fetches Patrick Steinhardt
2023-05-08 22:51 ` Glen Choo
2023-05-09 12:41 ` Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 2/8] fetch: split out tests for output format Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 3/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 4/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 5/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 6/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 7/8] fetch: move option related variables " Patrick Steinhardt
2023-05-03 11:34 ` [PATCH v3 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-05-08 23:42 ` Glen Choo
2023-05-09 12:41 ` Patrick Steinhardt
2023-05-09 0:03 ` Glen Choo
2023-05-03 16:48 ` [PATCH v3 0/8] fetch: introduce machine-parseable output Junio C Hamano
2023-05-03 16:53 ` Junio C Hamano
2023-05-04 7:57 ` Patrick Steinhardt
2023-05-09 0:06 ` Glen Choo
2023-05-09 12:42 ` Patrick Steinhardt
2023-05-09 13:01 ` [PATCH v4 " Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 1/8] fetch: fix `--no-recurse-submodules` with multi-remote fetches Patrick Steinhardt
2023-05-09 17:49 ` Junio C Hamano
2023-05-09 18:27 ` Glen Choo
2023-05-10 12:34 ` Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 2/8] fetch: split out tests for output format Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 3/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-05-09 17:58 ` Junio C Hamano
2023-05-10 12:34 ` Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 4/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-05-09 19:28 ` Junio C Hamano
2023-05-10 12:34 ` Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 5/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-05-09 20:19 ` Junio C Hamano
2023-05-10 12:35 ` Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 6/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-05-09 20:35 ` Junio C Hamano
2023-05-09 22:30 ` Glen Choo
2023-05-10 12:35 ` Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 7/8] fetch: move option related variables " Patrick Steinhardt
2023-05-09 13:02 ` [PATCH v4 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-05-09 20:43 ` Junio C Hamano
2023-05-10 12:35 ` Patrick Steinhardt
2023-05-10 12:33 ` [PATCH v5 0/9] fetch: introduce machine-parseable output Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 1/9] fetch: fix `--no-recurse-submodules` with multi-remote fetches Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 2/9] fetch: split out tests for output format Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 3/9] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 4/9] fetch: print left-hand side when fetching HEAD:foo Patrick Steinhardt
2023-05-12 0:16 ` Glen Choo
2023-05-13 16:59 ` Jeff King
2023-05-15 5:15 ` Patrick Steinhardt [this message]
2023-05-10 12:34 ` [PATCH v5 5/9] fetch: refactor calculation of the display table width Patrick Steinhardt
2023-05-12 0:49 ` Glen Choo
2023-05-10 12:34 ` [PATCH v5 6/9] fetch: introduce `display_format` enum Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 7/9] fetch: lift up parsing of "fetch.output" config variable Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 8/9] fetch: move option related variables into main function Patrick Steinhardt
2023-05-10 12:34 ` [PATCH v5 9/9] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-05-12 1:02 ` Glen Choo
2023-05-10 18:05 ` [PATCH v5 0/9] fetch: introduce machine-parseable output Junio C Hamano
2023-05-11 11:05 ` Patrick Steinhardt
2023-05-11 16:53 ` Junio C Hamano
2023-05-11 17:24 ` Felipe Contreras
2023-05-12 1:09 ` Glen Choo
2023-05-12 7:16 ` Patrick Steinhardt
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