From: Jani Nikula <jani@nikula.org>
To: David Bremner <david@tethera.net>, notmuch@notmuchmail.org
Subject: Re: [PATCH] lib: another iterator-temporary/stale-pointer bug
Date: Thu, 01 Jan 2015 16:49:31 +0200 [thread overview]
Message-ID: <87wq56wo78.fsf@nikula.org> (raw)
In-Reply-To: <1419763508-11902-1-git-send-email-david@tethera.net>
On Sun, 28 Dec 2014, David Bremner <david@tethera.net> wrote:
> Tamas Szakaly points out [1] that the bug fixed in 51b073c still
> exists in at least one place. This change follows the suggestion of
> [2] and creates a block scope temporary std::string to avoid the rules
> of iterators temporaries.
>
> [1]: id:20141226113755.GA64154@pamparam
> [2]: id:20141226230655.GA41992@pamparam
> ---
>
> I decided to take a more minimalist approach than [2]. In particular
> using "direntry" for two different things seemed slightly trickier
> than necessary, for no obvious performance gain (calling .c_str()
> should be cheap).
>
> lib/message.cc | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/lib/message.cc b/lib/message.cc
> index a7a13cc..bacb4d4 100644
> --- a/lib/message.cc
> +++ b/lib/message.cc
> @@ -641,15 +641,16 @@ _notmuch_message_add_directory_terms (void *ctx, notmuch_message_t *message)
> unsigned int directory_id;
> const char *direntry, *directory;
> char *colon;
> + const std::string term = *i;
You could use a reference here like in [2]. Either way, LGTM.
Jani.
>
> /* Terminate loop at first term without desired prefix. */
> - if (strncmp ((*i).c_str (), direntry_prefix, direntry_prefix_len))
> + if (strncmp (term.c_str (), direntry_prefix, direntry_prefix_len))
> break;
>
> /* Indicate that there are filenames remaining. */
> status = NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID;
>
> - direntry = (*i).c_str ();
> + direntry = term.c_str ();
> direntry += direntry_prefix_len;
>
> directory_id = strtol (direntry, &colon, 10);
> --
> 2.1.3
>
> _______________________________________________
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> notmuch@notmuchmail.org
> http://notmuchmail.org/mailman/listinfo/notmuch
next prev parent reply other threads:[~2015-01-01 14:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-26 11:37 BUG: Using pointer that points to a destructed string's content Tamas Szakaly
2014-12-26 22:03 ` David Bremner
2014-12-26 23:06 ` Tamas Szakaly
2014-12-28 10:45 ` [PATCH] lib: another iterator-temporary/stale-pointer bug David Bremner
2015-01-01 14:49 ` Jani Nikula [this message]
2015-01-02 16:20 ` [PATCH] lib: convert two "iterator copy strings" into references David Bremner
2015-01-02 17:52 ` Jani Nikula
2015-01-02 20:07 ` Tomi Ollila
2015-01-03 9:03 ` David Bremner
2014-12-27 8:33 ` [PATCH] lib: collapse computation of directory_id into a single expression David Bremner
2015-01-03 13:30 ` BUG: Using pointer that points to a destructed string's content David Bremner
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