[geary/wip/search-cleanup: 3/9] Fix critical trying to load a conversation with 0 email

[Michael Gratton <mjog src gnome org>]

commit 710f99df359b33663ee9b7f28b51323213912b90
Author: Michael Gratton <mike vee net>
Date:   Mon Feb 4 00:16:22 2019 +1100

    Fix critical trying to load a conversation with 0 email
    
    This can happen when the search is changing and a number of
    conversations are evaporating.

 src/client/application/geary-controller.vala | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/src/client/application/geary-controller.vala b/src/client/application/geary-controller.vala
index bb45ede4..904a7983 100644
--- a/src/client/application/geary-controller.vala
+++ b/src/client/application/geary-controller.vala
@@ -1271,7 +1271,13 @@ public class GearyController : Geary.BaseObject {
                 Geary.App.EmailStore? store = get_store_for_folder(
                     convo.base_folder
                 );
-                if (store != null) {
+
+                // It's possible for a conversation with zero email to
+                // be selected, when it has just evaporated after its
+                // last email was removed but the conversation monitor
+                // hasn't signalled its removal yet. In this case,
+                // just don't load it since it will soon disappear.
+                if (store != null && convo.get_count() > 0) {
                     viewer.load_conversation.begin(
                         convo,
                         store,