abrt version: 1.1.17
architecture: i686
Attached file: backtrace, 19433 bytes
cmdline: claws-mail
component: claws-mail
Attached file: coredump, 65204224 bytes
crash_function: mimeview_check_sig_cancel_thread
executable: /usr/bin/claws-mail
kernel: 2.6.35.11-83.fc14.i686.PAE
package: claws-mail-3.7.8-3.fc14
rating: 4
reason: Process /usr/bin/claws-mail was killed by signal 11 (SIGSEGV)
release: Fedora release 14 (Laughlin)
time: 1297611580
uid: 500

comment
-----
From the earlier backtrace:

> /usr/lib64/claws-mail/plugins/pgpcore.so
> /usr/lib64/claws-mail/plugins/pgpmime.so
> /usr/lib64/claws-mail/plugins/bogofilter.so

The mimeview.c code:

  /* creates a thread to check the signature, and a second one
   * to kill the first one after a timeout */

The mimeview_check_sig_cancel_thread() that crashes is the second thread (aka the "killer thread") that tries to cancel the first thread:

	/* too late, go away checker thread */
	debug_print("killing checker thread\n");
->	pthread_cancel(mimeview->check_data->th);

How to reproduce
-----
First tried to reproduce what is mentioned in comment 2, but then modified the test-case because I couldn't reproduce. It is not necessary to import any key manually:

1. delete the test GPG key from your keyring
2. in summary view, double-click a GPG signed message to open it in a new window (Ctrl+Alt+N or menu View > Open in new window)
3. click the "lock" icon at the message window's left bottom in quick succession (i.e. two or more times)
4. shortly after, close the window

Sometimes Claws Mail 3.7.8 crashes instantly. Other times it stays open but crashes as soon as one changes into a different folder.