diff -r 8409368bbfe6 -r f2b2fd93f05f DisplaySurface.st
--- a/DisplaySurface.st	Sat Jul 23 21:50:59 2016 +0200
+++ b/DisplaySurface.st	Mon Jul 25 10:40:28 2016 +0200
@@ -1770,13 +1770,14 @@
      suspend until the expose/noExpose event arrives.
      This is an X speciality - for devices which do not need this kind of
      asynchronous bit-blt confirmation, this is a noop.
+     Answer true if the sender is reqired to do a waitForExpose, false if not.
     "
 
     |wg|
 
     device scrollsAsynchronous ifFalse:[
-	self setGotExposeFlag.
-	^ self
+        self setGotExposeFlag.
+        ^ false
     ].
 
     self setGraphicsExposures:true.
@@ -1784,14 +1785,16 @@
     self clearGotExposeFlag.
     wg := self windowGroup.
     wg notNil ifTrue:[
-	"
-	 must process eny pending expose events, since
-	 usually the origin is changed soon so that previous
-	 expose events coordinates are invalid
-	"
-	wg processRealExposeEventsFor:self.
-	wg sensor catchExposeFor:self
-    ]
+        "
+         must process eny pending expose events, since
+         usually the origin is changed soon so that previous
+         expose events coordinates are invalid
+        "
+        wg processRealExposeEventsFor:self.
+        wg sensor catchExposeFor:self.
+        ^ true
+    ].
+    ^ false.
 
     "Modified: 6.8.1997 / 19:50:15 / cg"
 !