Changeset 168837 in webkit

Timestamp:

May 14, 2014 8:38:34 AM (10 years ago)

Author:

stavila@adobe.com

Message:

[CSS Regions] Add ASSERT to make sure using the flowThread cache does not return incorrect results
​https://bugs.webkit.org/show_bug.cgi?id=132906

Reviewed by Andrei Bucur.

If flowThreadContainingBlock() is called on an object which is in a different
flow thread than the one currently being laid out, this method will return an incorrect
result. I added an assertion for that to make sure we catch and treat any such scenarios.

No new tests required.

• rendering/RenderObject.cpp:

(WebCore::RenderObject::locateFlowThreadContainingBlockNoCache):
(WebCore::RenderObject::locateFlowThreadContainingBlock):

• rendering/RenderObject.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderObject.cpp (modified) (2 diffs)
• rendering/RenderObject.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2014-05-14  Radu Stavila  <stavila@adobe.com>
+
+        [CSS Regions] Add ASSERT to make sure using the flowThread cache does not return incorrect results
+        https://bugs.webkit.org/show_bug.cgi?id=132906
+
+        Reviewed by Andrei Bucur.
+
+        If flowThreadContainingBlock() is called on an object which is in a different
+        flow thread than the one currently being laid out, this method will return an incorrect
+        result. I added an assertion for that to make sure we catch and treat any such scenarios.
+
+        No new tests required.
+
+        * rendering/RenderObject.cpp:
+        (WebCore::RenderObject::locateFlowThreadContainingBlockNoCache):
+        (WebCore::RenderObject::locateFlowThreadContainingBlock):
+        * rendering/RenderObject.h:
+
 2014-05-14  Andrei Bucur  <abucur@adobe.com>
 

trunk/Source/WebCore/rendering/RenderObject.cpp

@@ -523 +523 @@
 }
 
-RenderFlowThread* RenderObject::locateFlowThreadContainingBlock() const
+RenderFlowThread* RenderObject::locateFlowThreadContainingBlockNoCache() const
 {
     ASSERT(flowThreadState() != NotInsideFlowThread);
 
-    // See if we have the thread cached because we're in the middle of layout.
-    RenderFlowThread* flowThread = view().flowThreadController().currentRenderFlowThread();
-    if (flowThread && (flowThreadState() == flowThread->flowThreadState()))
-        return flowThread;
-    
-    // Not in the middle of layout so have to find the thread the slow way.
     RenderObject* curr = const_cast<RenderObject*>(this);
     while (curr) {
@@ -540 +534 @@
     }
     return 0;
+}
+
+RenderFlowThread* RenderObject::locateFlowThreadContainingBlock() const
+{
+    ASSERT(flowThreadState() != NotInsideFlowThread);
+
+    // See if we have the thread cached because we're in the middle of layout.
+    RenderFlowThread* flowThread = view().flowThreadController().currentRenderFlowThread();
+    if (flowThread && (flowThreadState() == flowThread->flowThreadState())) {
+        // Make sure the slow path would return the same result as our cache.
+        ASSERT(flowThread == locateFlowThreadContainingBlockNoCache());
+        return flowThread;
+    }
+    
+    // Not in the middle of layout so have to find the thread the slow way.
+    return locateFlowThreadContainingBlockNoCache();
 }
 

trunk/Source/WebCore/rendering/RenderObject.h

@@ -890 +890 @@
 private:
     RenderFlowThread* locateFlowThreadContainingBlock() const;
+    
+    // This will walk the tree to find the flow thread.
+    RenderFlowThread* locateFlowThreadContainingBlockNoCache() const;
+    
     void removeFromRenderFlowThread();
     void removeFromRenderFlowThreadRecursive(RenderFlowThread*);