Changeset 237849 in webkit

Timestamp:

Nov 6, 2018 12:19:47 AM (5 years ago)

Author:

fred.wang@free.fr

Message:

Overlay with -webkit-overflow-scrolling:touch doesn't become scrollable after added text makes it taller
​https://bugs.webkit.org/show_bug.cgi?id=158342

Patch by Frederic Wang <​fwang@igalia.com> on 2018-11-06
Reviewed by Simon Fraser.

Source/WebCore:

Resizing the content of a -webkit-overflow-scrolling:touch overflow node on iOS may make it
scrollable. However, the RenderLayerBacking's scrolling layer is not properly created
when RenderLayerCompositor::updateScrollCoordinatedLayer is called and hence the UIProcess
receives a null UIScrollView pointer when ScrollingTreeScrollingNodeDelegateIOS performs the
associated update. In debug mode this hits an ASSERT and in release mode the overflow node
remains unscrollable from the user's point of view. This patch fixes this issue by ensuring
the RenderLayerBacking's scrolling layer is created during updateScrollCoordinatedStatus.

Test: fast/scrolling/ios/update-scroll-coordinated-status.html

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::updateScrollCoordinatedStatus): Call updateConfiguration()
to ensure the scrolling layer is present and indicate whether a rebuild is necessary.

LayoutTests:

Add a test to ensure the change of scrolling status is reflected in the layer and scrolling
trees. This test should also ASSERT in debug mode without the associated code change.

• fast/scrolling/ios/update-scroll-coordinated-status-expected.txt: Added.
• fast/scrolling/ios/update-scroll-coordinated-status.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/scrolling/ios/update-scroll-coordinated-status-expected.txt (added)
• LayoutTests/fast/scrolling/ios/update-scroll-coordinated-status.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerCompositor.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2018-11-06  Frederic Wang  <fwang@igalia.com>
+
+        Overlay with -webkit-overflow-scrolling:touch doesn't become scrollable after added text makes it taller
+        https://bugs.webkit.org/show_bug.cgi?id=158342
+
+        Reviewed by Simon Fraser.
+
+        Add a test to ensure the change of scrolling status is reflected in the layer and scrolling
+        trees. This test should also ASSERT in debug mode without the associated code change.
+
+        * fast/scrolling/ios/update-scroll-coordinated-status-expected.txt: Added.
+        * fast/scrolling/ios/update-scroll-coordinated-status.html: Added.
+
 2018-11-05  Wenson Hsieh  <wenson_hsieh@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2018-11-06  Frederic Wang  <fwang@igalia.com>
+
+        Overlay with -webkit-overflow-scrolling:touch doesn't become scrollable after added text makes it taller
+        https://bugs.webkit.org/show_bug.cgi?id=158342
+
+        Reviewed by Simon Fraser.
+
+        Resizing the content of a -webkit-overflow-scrolling:touch overflow node on iOS may make it
+        scrollable. However, the RenderLayerBacking's scrolling layer is not properly created
+        when RenderLayerCompositor::updateScrollCoordinatedLayer is called and hence the UIProcess
+        receives a null UIScrollView pointer when ScrollingTreeScrollingNodeDelegateIOS performs the
+        associated update. In debug mode this hits an ASSERT and in release mode the overflow node
+        remains unscrollable from the user's point of view. This patch fixes this issue by ensuring
+        the RenderLayerBacking's scrolling layer is created during updateScrollCoordinatedStatus.
+
+        Test: fast/scrolling/ios/update-scroll-coordinated-status.html
+
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::updateScrollCoordinatedStatus): Call updateConfiguration()
+        to ensure the scrolling layer is present and indicate whether a rebuild is necessary.
+
 2018-11-05  Zan Dobersek  <zdobersek@igalia.com>
 

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -3545 +3545 @@
         layer.backing()->setIsScrollCoordinatedWithViewportConstrainedRole(coordinationRoles.contains(ViewportConstrained));
 
+    if (layer.backing() && layer.backing()->updateConfiguration())
+        setCompositingLayersNeedRebuild();
+
     if (coordinationRoles && canCoordinateScrollingForLayer(layer)) {
         if (m_scrollCoordinatedLayers.add(&layer).isNewEntry)