Fix out of range exception when there are no messages in conversation

SERVCUBED · golf1052 · commit 8951066c3979 · 2017-10-14T12:37:04.000-07:00
diff --git a/Signal-Windows/Controls/Conversation.xaml.cs b/Signal-Windows/Controls/Conversation.xaml.cs
@@ -223,6 +223,8 @@ private async void TextBox_KeyDown(object sender, KeyRoutedEventArgs e)
 
         private void ScrollToBottom()
         {
+            if (ConversationItemsControl.Items.Count == 0)
+                return;
             var lastMsg = ConversationItemsControl.Items[ConversationItemsControl.Items.Count - 1] as SignalMessageContainer;
             Debug.WriteLine($"scroll to {lastMsg}");
             ConversationItemsControl.ScrollIntoView(lastMsg);

Original file line number	Diff line number	Diff line change
`@@ -223,6 +223,8 @@ private async void TextBox_KeyDown(object sender, KeyRoutedEventArgs e)`
`223`	`223`
`224`	`224`	`private void ScrollToBottom()`
`225`	`225`	`{`
	`226`	`+ if (ConversationItemsControl.Items.Count == 0)`
	`227`	`+ return;`
`226`	`228`	`var lastMsg = ConversationItemsControl.Items[ConversationItemsControl.Items.Count - 1] as SignalMessageContainer;`
`227`	`229`	`Debug.WriteLine($"scroll to {lastMsg}");`
`228`	`230`	`ConversationItemsControl.ScrollIntoView(lastMsg);`