Changeset 140576 in webkit

Timestamp:

Jan 23, 2013, 12:54:07 PM (12 years ago)

Author:

tony@chromium.org

Message:

Incorrect scrollable height during simplified layout
​https://bugs.webkit.org/show_bug.cgi?id=107193

Reviewed by David Hyatt.

Source/WebCore:

When computing overflow we need the height of the block before
it was clamped (i.e., before updateLogicalHeight() has been called).

During simplified layout, we don't have this information and we were
using the clamped height by mistake. To fix this, we now store the
pre-clamped height on RenderOverflow so we can properly compute
overflow.

Test: fast/overflow/height-during-simplified-layout.html

• rendering/RenderBlock.cpp:

(WebCore::RenderBlock::computeOverflow): Save the height if we have overflow.
(WebCore::RenderBlock::simplifiedLayout): If we have overflow, use the height that we saved
in computeOverflow.

• rendering/RenderOverflow.h:

(WebCore::RenderOverflow::layoutClientAfterEdge):
(WebCore::RenderOverflow::setLayoutClientAfterEdge):
(RenderOverflow): Add a member variable to save the height.

LayoutTests:

• fast/overflow/height-during-simplified-layout-expected.txt: Added.
• fast/overflow/height-during-simplified-layout.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/overflow/height-during-simplified-layout-expected.txt (added)
• LayoutTests/fast/overflow/height-during-simplified-layout.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderBlock.cpp (modified) (2 diffs)
• Source/WebCore/rendering/RenderOverflow.h (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-01-23  Tony Chang  <tony@chromium.org>
+
+        Incorrect scrollable height during simplified layout
+        https://bugs.webkit.org/show_bug.cgi?id=107193
+
+        Reviewed by David Hyatt.
+
+        * fast/overflow/height-during-simplified-layout-expected.txt: Added.
+        * fast/overflow/height-during-simplified-layout.html: Added.
+
 2013-01-23  Robert Hogan  <robert@webkit.org>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-01-23  Tony Chang  <tony@chromium.org>
+
+        Incorrect scrollable height during simplified layout
+        https://bugs.webkit.org/show_bug.cgi?id=107193
+
+        Reviewed by David Hyatt.
+
+        When computing overflow we need the height of the block before
+        it was clamped (i.e., before updateLogicalHeight() has been called).
+
+        During simplified layout, we don't have this information and we were
+        using the clamped height by mistake. To fix this, we now store the
+        pre-clamped height on RenderOverflow so we can properly compute
+        overflow.
+
+        Test: fast/overflow/height-during-simplified-layout.html
+
+        * rendering/RenderBlock.cpp:
+        (WebCore::RenderBlock::computeOverflow): Save the height if we have overflow.
+        (WebCore::RenderBlock::simplifiedLayout): If we have overflow, use the height that we saved
+        in computeOverflow.
+        * rendering/RenderOverflow.h:
+        (WebCore::RenderOverflow::layoutClientAfterEdge):
+        (WebCore::RenderOverflow::setLayoutClientAfterEdge):
+        (RenderOverflow): Add a member variable to save the height.
+
 2013-01-23  Tom Sepez  <tsepez@chromium.org>
 

trunk/Source/WebCore/rendering/RenderBlock.cpp

@@ -1675 +1675 @@
             rectToApply = LayoutRect(clientRect.x(), clientRect.y(), max<LayoutUnit>(0, oldClientAfterEdge - clientRect.x()), 1);
         addLayoutOverflow(rectToApply);
+        if (hasRenderOverflow())
+            m_overflow->setLayoutClientAfterEdge(oldClientAfterEdge);
     }
         
@@ -2607 +2609 @@
     // For now just always recompute overflow.  This is no worse performance-wise than the old code that called rightmostPosition and
     // lowestPosition on every relayout so it's not a regression.
+    // computeOverflow expects the bottom edge before we clamp our height. Since this information isn't available during
+    // simplifiedLayout, we cache the value in m_overflow.
+    LayoutUnit oldClientAfterEdge = hasRenderOverflow() ? m_overflow->layoutClientAfterEdge() : clientLogicalBottom();
     m_overflow.clear();
-    computeOverflow(clientLogicalBottom(), true);
+    computeOverflow(oldClientAfterEdge, true);
 
     statePusher.pop();

trunk/Source/WebCore/rendering/RenderOverflow.h

@@ -68 +68 @@
     void setVisualOverflow(const LayoutRect&);
 
+    LayoutUnit layoutClientAfterEdge() const { return m_layoutClientAfterEdge; }
+    void setLayoutClientAfterEdge(LayoutUnit clientAfterEdge) { m_layoutClientAfterEdge = clientAfterEdge; }
+
 private:
     LayoutRect m_layoutOverflow;
     LayoutRect m_visualOverflow;
+
+    LayoutUnit m_layoutClientAfterEdge;
 };