[evolution] Bug #683665 - Crash on displaying message with broken Content-Type attachment

[Milan Crha <mcrha src gnome org>]

commit 4a07071e2f72af2301106f5b2a03177675a7a5f1
Author: Lucian Langa <lucilanga gnome org>
Date:   Tue Sep 11 16:31:35 2012 +0200

    Bug #683665 - Crash on displaying message with broken Content-Type attachment

 em-format/e-mail-extension-registry.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/em-format/e-mail-extension-registry.c b/em-format/e-mail-extension-registry.c
index 00d6b55..3482286 100644
--- a/em-format/e-mail-extension-registry.c
+++ b/em-format/e-mail-extension-registry.c
@@ -217,6 +217,9 @@ e_mail_extension_registry_get_fallback (EMailExtensionRegistry *reg,
 	g_return_val_if_fail (mime_type && *mime_type, NULL);
 
 	s = strchr (mime_type, '/');
+	if (!s)
+		return NULL;
+
 	len = s - mime_type;
 
 	s = g_alloca (len);