Fix bad FLTK window resize handling on OS X.

http://www.fltk.org/str.php?L2775


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4813 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/fltk/src/Fl_cocoa.mm b/common/fltk/src/Fl_cocoa.mm
index 5fad4fe..19a58ac 100644
--- a/common/fltk/src/Fl_cocoa.mm
+++ b/common/fltk/src/Fl_cocoa.mm
@@ -2598,6 +2598,12 @@
       pt.y = [[(NSWindow*)i->xid screen] frame].size.height - (Y + h());
       [(NSWindow*)i->xid setFrameOrigin:pt];
     }
+    // setFrame and setFrameOrigin are only requests to the system to
+    // do a resize or move. We will get callbacks later if the system allowed
+    // this, and possibly with adjusted values. We avoid processing until
+    // that happens (which usually happens directly as setFrame[Origin] is
+    // called).
+    return;
   }
   resize_from_system = 0;
   if (is_a_resize) {