Remove a compilation warning appearing with Mac OS 10.11 +

explain better the intent of this thread creation.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10840 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 4 insertions, 3 deletions

diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index 8a24b9588..43e26ebb0 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -1731,9 +1731,10 @@ void fl_open_display() {
 						 name:NSWindowWillCloseNotification 
 					       object:nil];
     if (![NSThread isMultiThreaded]) {
-      // necessary for secondary pthreads to be allowed to use cocoa,
-      // especially to create an NSAutoreleasePool.
-      [NSThread detachNewThreadSelector:nil toTarget:nil withObject:nil];
+      // With older OS X versions, it is necessary to create one thread for secondary pthreads to be
+      // allowed to use cocoa, especially to create an NSAutoreleasePool.
+      // We create a thread that will complete very fast:
+      [NSThread detachNewThreadSelector:@selector(unhide:) toTarget:NSApp withObject:nil];
     }
   }
 }