From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Johannes Sixt <j.sixt@viscovery.net>, git@vger.kernel.org
Subject: Re: [PATCH 7/4] submodule: clarify logic in show_submodule_summary
Date: Fri, 22 Mar 2013 14:10:42 -0700 [thread overview]
Message-ID: <7v620j6sz1.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <20130322161955.GA25857@sigill.intra.peff.net> (Jeff King's message of "Fri, 22 Mar 2013 12:19:56 -0400")
Jeff King <peff@peff.net> writes:
> There are two uses of the "left" and "right" commit
> variables that make it hard to be sure what values they
> have (both for the reader, and for gcc, which wrongly
> complains that they might be used uninitialized).
>
> The functions starts with a cascading if statement, checking
> that the input sha1s exist, and finally working up to
> preparing a revision walk. We only prepare the walk if the
> cascading conditional did not find any problems, which we
> check by seeing whether it set the "message" variable or
> not. It's simpler and more obvious to just add a condition
> to the end of the cascade.
>
> Later, we check the same "message" variable when deciding
> whether to clear commit marks on the left/right commits; if
> it is set, we presumably never started the walk. This is
> wrong, though; we might have started the walk and munged
> commit flags, only to encounter an error afterwards. We
> should always clear the flags on left/right if they exist,
> whether the walk was successful or not.
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
Looks good. Thanks.
> submodule.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/submodule.c b/submodule.c
> index 9ba1496..975bc87 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -261,7 +261,7 @@ void show_submodule_summary(FILE *f, const char *path,
> const char *del, const char *add, const char *reset)
> {
> struct rev_info rev;
> - struct commit *left = left, *right = right;
> + struct commit *left = NULL, *right = NULL;
> const char *message = NULL;
> struct strbuf sb = STRBUF_INIT;
> int fast_forward = 0, fast_backward = 0;
> @@ -275,10 +275,8 @@ void show_submodule_summary(FILE *f, const char *path,
> else if (!(left = lookup_commit_reference(one)) ||
> !(right = lookup_commit_reference(two)))
> message = "(commits not present)";
> -
> - if (!message &&
> - prepare_submodule_summary(&rev, path, left, right,
> - &fast_forward, &fast_backward))
> + else if (prepare_submodule_summary(&rev, path, left, right,
> + &fast_forward, &fast_backward))
> message = "(revision walker failed)";
>
> if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
> @@ -302,11 +300,12 @@ void show_submodule_summary(FILE *f, const char *path,
> strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
> fwrite(sb.buf, sb.len, 1, f);
>
> - if (!message) {
> + if (!message) /* only NULL if we succeeded in setting up the walk */
> print_submodule_summary(&rev, f, del, add, reset);
> + if (left)
> clear_commit_marks(left, ~0);
> + if (right)
> clear_commit_marks(right, ~0);
> - }
>
> strbuf_release(&sb);
> }
next prev parent reply other threads:[~2013-03-22 21:11 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 11:03 [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Jeff King
2013-03-21 11:05 ` [PATCH 1/4] wt-status: fix possible use of uninitialized variable Jeff King
2013-03-21 19:49 ` Jonathan Nieder
2013-03-21 19:55 ` Junio C Hamano
2013-03-21 19:58 ` Jonathan Nieder
2013-03-22 16:15 ` Jeff King
2013-03-21 11:08 ` [PATCH 2/4] fast-import: use pointer-to-pointer to keep list tail Jeff King
2013-03-21 20:43 ` Jonathan Nieder
2013-03-21 11:10 ` [PATCH 3/4] drop some obsolete "x = x" compiler warning hacks Jeff King
2013-03-21 15:16 ` Erik Faye-Lund
2013-03-21 20:47 ` Jonathan Nieder
2013-03-24 7:17 ` Torsten Bögershausen
2013-03-21 11:13 ` [PATCH 4/4] transport: drop "int cmp = cmp" hack Jeff King
2013-03-21 20:59 ` Jonathan Nieder
2013-03-24 4:00 ` Junio C Hamano
2013-03-24 9:32 ` Jeff King
2013-03-24 14:54 ` Torsten Bögershausen
2013-03-25 19:50 ` Junio C Hamano
2013-03-25 21:06 ` Jeff King
2013-03-25 21:55 ` Junio C Hamano
2013-03-21 11:45 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Johannes Sixt
2013-03-21 11:55 ` Jeff King
2013-03-21 14:58 ` Junio C Hamano
2013-03-21 15:19 ` Junio C Hamano
2013-03-21 15:44 ` Jeff King
2013-03-21 15:44 ` [PATCH 5/4] fast-import: clarify "inline" logic in file_change_m Jeff King
2013-03-21 15:45 ` [PATCH 6/4] run-command: always set failed_errno in start_command Jeff King
2013-03-21 21:02 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Jonathan Nieder
2013-03-22 16:18 ` Jeff King
2013-03-22 16:19 ` [PATCH 7/4] submodule: clarify logic in show_submodule_summary Jeff King
2013-03-22 21:10 ` Junio C Hamano [this message]
2013-03-22 16:21 ` [PATCH 8/4] match-trees: drop "x = x" initializations Jeff King
2013-03-22 21:26 ` Junio C Hamano
2013-03-22 21:33 ` Junio C Hamano
2013-03-22 21:36 ` Jeff King
2013-03-23 18:57 ` René Scharfe
2013-03-24 4:55 ` Junio C Hamano
2013-03-24 10:01 ` Jeff King
2013-03-24 22:46 ` René Scharfe
2013-03-25 16:10 ` Junio C Hamano
2013-03-21 13:44 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Joachim Schmitz
2013-03-21 13:56 ` Joachim Schmitz
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