Auto-merge pull request #2981 from livecodefraser/bugfix-15878-6.7

livecode-vulcan · livecode-vulcan · commit 64f47f0a4a0c · 2015-10-05T10:06:58.000+01:00
[[ Bugfix 15878 ]] Fix a crash caused by waiting during modal session setup

Creating a modal window session on Cocoa can trigger event processing
(e.g. because another window lost focus). Waiting during these
events caused a crash because the wait loop attempted to run the
modal session that hadn't actually been created yet.
diff --git a/docs/notes/bugfix-15878.md b/docs/notes/bugfix-15878.md
@@ -0,0 +1,2 @@
+# Fix a crash caused by waiting during modal window setup
+
diff --git a/engine/src/mac-core.mm b/engine/src/mac-core.mm
@@ -736,7 +736,11 @@ bool MCPlatformWaitForEvent(double p_duration, bool p_blocking)
                                  untilDate: [NSDate dateWithTimeIntervalSinceNow: p_duration]
                                     inMode: p_blocking ? NSEventTrackingRunLoopMode : NSDefaultRunLoopMode
                                    dequeue: YES];
-	if (t_modal)
+    
+    // Run the modal session, if it has been created yet (it might not if this
+    // wait was triggered by reacting to an event caused as part of creating
+    // the modal session, e.g. when losing window focus).
+	if (t_modal && s_modal_sessions[s_modal_session_count - 1].session != nil)
 		[NSApp runModalSession: s_modal_sessions[s_modal_session_count - 1] . session];
     
 	s_in_blocking_wait = false;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+# Fix a crash caused by waiting during modal window setup`
	`2`	`+`