[PATCH] lib: another iterator-temporary/stale-pointer bug

diff --git a/cb/f2af3d11a9007ffcc96e4f0444fe43a3984050 b/cb/f2af3d11a9007ffcc96e4f0444fe43a3984050
new file mode 100644 (file)
index 0000000..8ad176a
--- /dev/null
+++ b/cb/f2af3d11a9007ffcc96e4f0444fe43a3984050
@@ -0,0 +1,91 @@
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+From: David Bremner <david@tethera.net>\r
+To: notmuch@notmuchmail.org\r
+Subject: [PATCH] lib: another iterator-temporary/stale-pointer bug\r
+Date: Sun, 28 Dec 2014 11:45:08 +0100\r
+Message-Id: <1419763508-11902-1-git-send-email-david@tethera.net>\r
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+References: <20141226230655.GA41992@pamparam>\r
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+\r
+Tamas Szakaly points out [1] that the bug fixed in 51b073c still\r
+exists in at least one place. This change follows the suggestion of\r
+[2] and creates a block scope temporary std::string to avoid the rules\r
+of iterators temporaries.\r
+\r
+[1]: id:20141226113755.GA64154@pamparam\r
+[2]: id:20141226230655.GA41992@pamparam\r
+---\r
+\r
+I decided to take a more minimalist approach than [2]. In particular\r
+using "direntry" for two different things seemed slightly trickier\r
+than necessary, for no obvious performance gain (calling .c_str()\r
+should be cheap).\r
+\r
+lib/message.cc | 5 +++--\r
+ 1 file changed, 3 insertions(+), 2 deletions(-)\r
+\r
+diff --git a/lib/message.cc b/lib/message.cc\r
+index a7a13cc..bacb4d4 100644\r
+--- a/lib/message.cc\r
++++ b/lib/message.cc\r
+@@ -641,15 +641,16 @@ _notmuch_message_add_directory_terms (void *ctx, notmuch_message_t *message)\r
+       unsigned int directory_id;\r
+       const char *direntry, *directory;\r
+       char *colon;\r
++      const std::string term = *i;\r
+ \r
+       /* Terminate loop at first term without desired prefix. */\r
+-      if (strncmp ((*i).c_str (), direntry_prefix, direntry_prefix_len))\r
++      if (strncmp (term.c_str (), direntry_prefix, direntry_prefix_len))\r
+           break;\r
+ \r
+       /* Indicate that there are filenames remaining. */\r
+       status = NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID;\r
+ \r
+-      direntry = (*i).c_str ();\r
++      direntry = term.c_str ();\r
+       direntry += direntry_prefix_len;\r
+ \r
+       directory_id = strtol (direntry, &colon, 10);\r
+-- \r
+2.1.3\r
+\r