Changeset 201407 in webkit for trunk/Source/WebCore/rendering/RenderBox.cpp

Timestamp:

May 25, 2016, 4:01:51 PM (10 years ago)

Author:

Alan Bujtas

Message:

Setting overflow:hidden does not always repaint clipped content.
​https://bugs.webkit.org/show_bug.cgi?id=116994
rdar://problem/26476697

Issue repaint for both layout and visual overflow rects when the container starts
clipping overflow content.

Reviewed by David Hyatt.

Source/WebCore:

Test: fast/repaint/overflow-hidden-repaint.html

• rendering/RenderBox.cpp:

(WebCore::RenderBox::updateFromStyle):

LayoutTests:

• fast/repaint/overflow-hidden-repaint-expected.html: Added.
• fast/repaint/overflow-hidden-repaint.html: Added.

File:

• trunk/Source/WebCore/rendering/RenderBox.cpp (modified) (1 diff)

trunk/Source/WebCore/rendering/RenderBox.cpp

@@ -517 +517 @@
             }
         }
-        
         // Check for overflow clip.
         // It's sufficient to just check one direction, since it's illegal to have visible on only one overflow value.
         if (boxHasOverflowClip) {
-            if (!s_hadOverflowClip)
-                // Erase the overflow
-                repaint();
+            if (!s_hadOverflowClip && hasRenderOverflow()) {
+                // Erase the overflow.
+                // Overflow changes have to result in immediate repaints of the entire layout overflow area because
+                // repaints issued by removal of descendants get clipped using the updated style when they shouldn't.
+                repaintRectangle(visualOverflowRect());
+                repaintRectangle(layoutOverflowRect());
+            }
             setHasOverflowClip();
         }
     }
-
     setHasTransformRelatedProperty(styleToUse.hasTransformRelatedProperty());
     setHasReflection(styleToUse.boxReflect());