Handle group quit sync messages

Previously, we would incorrectly reject group updates originating from a
linked device instructing us to remove ourselves from the group.

// FREEBIE

js/libtextsecure.js

@@ -37062,7 +37062,11 @@ MessageReceiver.prototype = {
                     case textsecure.protobuf.GroupContext.Type.QUIT:
                         decrypted.body = null;
                         decrypted.attachments = [];
-                        return textsecure.storage.groups.removeNumber(decrypted.group.id, source);
+                        if (source === this.number) {
+                            return textsecure.storage.groups.deleteGroup(decrypted.group.id);
+                        } else {
+                            return textsecure.storage.groups.removeNumber(decrypted.group.id, source);
+                        }
                     case textsecure.protobuf.GroupContext.Type.DELIVER:
                         decrypted.group.name = null;
                         decrypted.group.members = [];
@@ -37073,7 +37077,7 @@ MessageReceiver.prototype = {
                         throw new Error("Unknown group message type");
                     }
                 }
-            }));
+            }.bind(this)));
         }
 
         for (var i in decrypted.attachments) {

js/models/messages.js

@@ -280,7 +280,11 @@
                         }
                     }
                     else if (dataMessage.group.type === textsecure.protobuf.GroupContext.Type.QUIT) {
-                        group_update = { left: source };
+                        if (source == textsecure.storage.user.getNumber()) {
+                            group_update = { left: "You" };
+                        } else {
+                            group_update = { left: source };
+                        }
                         attributes.members = _.without(conversation.get('members'), source);
                     }
 

libtextsecure/message_receiver.js

@@ -331,7 +331,11 @@ MessageReceiver.prototype = {
                     case textsecure.protobuf.GroupContext.Type.QUIT:
                         decrypted.body = null;
                         decrypted.attachments = [];
-                        return textsecure.storage.groups.removeNumber(decrypted.group.id, source);
+                        if (source === this.number) {
+                            return textsecure.storage.groups.deleteGroup(decrypted.group.id);
+                        } else {
+                            return textsecure.storage.groups.removeNumber(decrypted.group.id, source);
+                        }
                     case textsecure.protobuf.GroupContext.Type.DELIVER:
                         decrypted.group.name = null;
                         decrypted.group.members = [];
@@ -342,7 +346,7 @@ MessageReceiver.prototype = {
                         throw new Error("Unknown group message type");
                     }
                 }
-            }));
+            }.bind(this)));
         }
 
         for (var i in decrypted.attachments) {