pidgin/pidgin

Fix an assert in purple_markup_html_to_xhtml
release-2.x.y
2021-09-15, Elliott Sales de Andrade
cb21c7484e4c
Fix an assert in purple_markup_html_to_xhtml

While `g_string_free` is NULL-safe, the assert for passing it in breaks
ossfuzz. This can happen if there is no `src=` in the `img` as expected.

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35029

Testing Done:
Ran the test case from the bug against `fuzz_html_to_xhtml`

Reviewed at https://reviews.imfreedom.org/r/921/
/*
* purple
*
* Purple is the legal property of its developers, whose names are too numerous
* to list here. Please refer to the COPYRIGHT file distributed with this
* source distribution.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA
*
*/
#ifndef _DBUS_PURPLE_H_
#define _DBUS_PURPLE_H_
#define DBUS_SERVICE_PURPLE "im.pidgin.purple.PurpleService"
#define DBUS_PATH_PURPLE "/im/pidgin/purple/PurpleObject"
#define DBUS_INTERFACE_PURPLE "im.pidgin.purple.PurpleInterface"
#endif /* _DBUS_PURPLE_H_ */