From 383f4dcbe6c4caebf91f76a9e65025f9a7de3505 Mon Sep 17 00:00:00 2001 From: David Bremner Date: Sun, 28 Dec 2014 11:45:08 +0100 Subject: [PATCH] [PATCH] lib: another iterator-temporary/stale-pointer bug --- cb/f2af3d11a9007ffcc96e4f0444fe43a3984050 | 91 +++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 cb/f2af3d11a9007ffcc96e4f0444fe43a3984050 diff --git a/cb/f2af3d11a9007ffcc96e4f0444fe43a3984050 b/cb/f2af3d11a9007ffcc96e4f0444fe43a3984050 new file mode 100644 index 000000000..8ad176aa8 --- /dev/null +++ b/cb/f2af3d11a9007ffcc96e4f0444fe43a3984050 @@ -0,0 +1,91 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 6A0F2431E82 + for ; Sun, 28 Dec 2014 02:45:43 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 0 +X-Spam-Level: +X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] + autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id yneXMn95Pp1K for ; + Sun, 28 Dec 2014 02:45:40 -0800 (PST) +Received: from yantan.tethera.net (yantan.tethera.net [199.188.72.155]) + (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) + (No client certificate requested) + by olra.theworths.org (Postfix) with ESMTPS id 376F6431FAE + for ; Sun, 28 Dec 2014 02:45:40 -0800 (PST) +Received: from remotemail by yantan.tethera.net with local (Exim 4.80) + (envelope-from ) + id 1Y5BLs-0007ep-Jh; Sun, 28 Dec 2014 06:45:36 -0400 +Received: (nullmailer pid 12358 invoked by uid 1000); Sun, 28 Dec 2014 + 10:45:31 -0000 +From: David Bremner +To: notmuch@notmuchmail.org +Subject: [PATCH] lib: another iterator-temporary/stale-pointer bug +Date: Sun, 28 Dec 2014 11:45:08 +0100 +Message-Id: <1419763508-11902-1-git-send-email-david@tethera.net> +X-Mailer: git-send-email 2.1.3 +In-Reply-To: <20141226230655.GA41992@pamparam> +References: <20141226230655.GA41992@pamparam> +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Sun, 28 Dec 2014 10:45:43 -0000 + +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; + + /* 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 + -- 2.26.2