Changeset 295556 in webkit

Timestamp:

Jun 15, 2022 6:43:53 AM (2 years ago)

Author:

Alan Bujtas

Message:

REGRESSION (r289443): Page contents disappear after entering a letter in the username field of bmoharris.com
​https://bugs.webkit.org/show_bug.cgi?id=241625
<rdar://93516876>

Reviewed by Simon Fraser.

overflow: clip forbids scrolling entirely, through any mechanism (​https://drafts.csswg.org/css-overflow/#propdef-overflow)

• LayoutTests/fast/scrolling/scrollIntoView-with-overflow-clip-expected.html: Added.
• LayoutTests/fast/scrolling/scrollIntoView-with-overflow-clip.html: Added.
• LayoutTests/fast/scrolling/selection-reveal-with-overflow-clip-expected.html: Added.
• LayoutTests/fast/scrolling/selection-reveal-with-overflow-clip.html: Added.
• Source/WebCore/rendering/RenderLayer.cpp:

(WebCore::RenderLayer::allowsCurrentScroll const): Make sure the content is not scrollable when overflow: clip is set on the renderer.

Canonical link: ​https://commits.webkit.org/251561@main

Location:

trunk

Files:

• LayoutTests/fast/scrolling/scrollIntoView-with-overflow-clip-expected.html (added)
• LayoutTests/fast/scrolling/scrollIntoView-with-overflow-clip.html (added)
• LayoutTests/fast/scrolling/selection-reveal-with-overflow-clip-expected.html (added)
• LayoutTests/fast/scrolling/selection-reveal-with-overflow-clip.html (added)
• Source/WebCore/rendering/RenderLayer.cpp (modified) (1 diff)

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -2516 +2516 @@
         return false;
 
-    RenderBox* box = renderBox();
-    ASSERT(box); // Only boxes can have overflowClip set.
-
-    if (renderer().frame().eventHandler().autoscrollInProgress()) {
+    // Only boxes can have overflowClip set.
+    auto& box = *renderBox();
+
+    if (box.frame().eventHandler().autoscrollInProgress()) {
         // The "programmatically" here is misleading; this asks whether the box has scrollable overflow,
         // or is a special case like a form control.
-        return box->canBeProgramaticallyScrolled();
-    }
-
-    // Programmatic scrolls can scroll overflow:hidden.
-    return box->hasHorizontalOverflow() || box->hasVerticalOverflow();
+        return box.canBeProgramaticallyScrolled();
+    }
+
+    // Programmatic scrolls can scroll overflow: hidden but not overflow: clip.
+    return box.hasPotentiallyScrollableOverflow() && (box.hasHorizontalOverflow() || box.hasVerticalOverflow());
 }