[geary] Fix null reference assertion in conversation viewer

[Jim Nelson <jnelson src gnome org>]

commit 6046170063e529b5826768ff6471f7dab8113d1f
Author: Jim Nelson <jim yorba org>
Date:   Sat Sep 13 19:46:02 2014 -0700

    Fix null reference assertion in conversation viewer
    
    When an email arrives with no From:, the conversation viewer has a
    soft assertion due to not checking for null.

 .../conversation-viewer/conversation-viewer.vala   |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/client/conversation-viewer/conversation-viewer.vala 
b/src/client/conversation-viewer/conversation-viewer.vala
index 312ed4b..3c6d777 100644
--- a/src/client/conversation-viewer/conversation-viewer.vala
+++ b/src/client/conversation-viewer/conversation-viewer.vala
@@ -500,7 +500,7 @@ public class ConversationViewer : Gtk.Box {
             if (email.is_unread() == Geary.Trillian.FALSE) {
                 div_message.get_class_list().add("hide");
             }
-            if (email.from.contains_normalized(current_account_information.email)) {
+            if (email.from != null && email.from.contains_normalized(current_account_information.email)) {
                 div_message.get_class_list().add("sent");
             }
         } catch (Error setup_error) {