Bug 536588: [Cocoa][GTK] GC.copyArea() doesn't work for StyledText

Though the paint event sent by GC.copyArea() is unexpected, we can't
ignore it. It is required for GC.copyArea to work with custom controls.
The fix is to prevent recursive calls to
cacheDisplayInRect_toBitmapImageRep.

Change-Id: I7ee99d3dd6a2824010ea3a1fbc4c36c2a09e1763
(cherry picked from commit 36bd428f1c9a3c2dfa7b0d8eab63495b292687e1)

1 files changed, 7 insertions, 8 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Control.java
index bc09cd7d7c..5f0d5105f8 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Control.java
@@ -72,7 +72,7 @@ public abstract class Control extends Widget implements Drawable {
 	NSBezierPath regionPath;
 	long /*int*/ visibleRgn;
 	Accessible accessible;
-	boolean ignorePaint;
+	boolean inCacheDisplayInRect;
 	boolean touchEnabled;
 
 	final static int CLIPPING = 1 << 10;
@@ -1263,7 +1263,6 @@ boolean drawsBackground() {
 
 @Override
 void drawWidget (long /*int*/ id, NSGraphicsContext context, NSRect rect) {
-	if (ignorePaint) return;
 	if (id != paintView().id) return;
 	if (!hooks (SWT.Paint) && !filters (SWT.Paint)) return;
 
@@ -3973,14 +3972,14 @@ void cacheDisplayInRect_toBitmapImageRep (long id, long sel, NSRect rect, long r
 	 * When a GC is created with a control as the Drawable and GC.copyArea() is
 	 * called, a SWT.Paint event will be sent, unexpectedly. This happens because
 	 * NSView.cacheDisplayInRect() calls drawRect() which causes a SWT.Paint event
-	 * to be sent. The fix is to ignore this paint event and prevent SWT from
-	 * sending it to the clients.
-	 * In the callback, set the ignorePaint flag, then call the Cocoa
-	 * implementation of cacheDisplayInRect_toBitmapImageRep(), then reset the ignorePaint flag.
+	 * to be sent. This leads to recursion if GC.copyArea() is called inside the PaintListener.
+	 *
+	 * The fix is to prevent recursive calls to cacheDisplayInRect_toBitmapImageRep.
 	 */
-	ignorePaint = true;
+	if (inCacheDisplayInRect) return;
+	inCacheDisplayInRect = true;
 	super.cacheDisplayInRect_toBitmapImageRep(id, sel, rect, rep);
-	ignorePaint = false;
+	inCacheDisplayInRect = false;
 }
 
 /**