Changeset 95228 in webkit

Timestamp:

Sep 15, 2011 2:21:11 PM (13 years ago)

Author:

aestes@apple.com

Message:

Having an empty listener to beforeload events changes the behavior of other scripts
​https://bugs.webkit.org/show_bug.cgi?id=45586

Reviewed by Darin Adler.

Source/WebCore:

Test: fast/dom/beforeload/cached-image-before-load.html

When loading a cached image after a beforeload handler has been
installed on the document, ImageLoader would dispatch both the
beforeload and load events asynchronously in such a way that caused
load to fire first. Since a side effect of firing the beforeload event
is to wire up the CachedImage to its associated RenderImage object,
this work was not done by the time load fired, and scripts that queried
renderer-dependent attributes of the image in an onload handler would
get bogus values in return.

Fix this by ensuring load fires after beforeload in the cached image case.

• loader/ImageLoader.cpp:

(WebCore::ImageLoader::updateFromElement): Call setClient() after
dispatching beforeload, since setClient() will dispatch the load event
if the image is cached.

LayoutTests:

• fast/dom/beforeload/cached-image-before-load-expected.txt: Added.
• fast/dom/beforeload/cached-image-before-load.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/dom/beforeload/cached-image-before-load-expected.txt (added)
• LayoutTests/fast/dom/beforeload/cached-image-before-load.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/loader/ImageLoader.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2011-09-15  Andy Estes  <aestes@apple.com>
+
+        Having an empty listener to beforeload events changes the behavior of other scripts
+        https://bugs.webkit.org/show_bug.cgi?id=45586
+
+        Reviewed by Darin Adler.
+
+        * fast/dom/beforeload/cached-image-before-load-expected.txt: Added.
+        * fast/dom/beforeload/cached-image-before-load.html: Added.
+
 2011-09-15  Jon Lee  <jonlee@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2011-09-15  Andy Estes  <aestes@apple.com>
+
+        Having an empty listener to beforeload events changes the behavior of other scripts
+        https://bugs.webkit.org/show_bug.cgi?id=45586
+
+        Reviewed by Darin Adler.
+
+        Test: fast/dom/beforeload/cached-image-before-load.html
+        
+        When loading a cached image after a beforeload handler has been
+        installed on the document, ImageLoader would dispatch both the
+        beforeload and load events asynchronously in such a way that caused
+        load to fire first. Since a side effect of firing the beforeload event
+        is to wire up the CachedImage to its associated RenderImage object,
+        this work was not done by the time load fired, and scripts that queried
+        renderer-dependent attributes of the image in an onload handler would
+        get bogus values in return.
+
+        Fix this by ensuring load fires after beforeload in the cached image case.
+
+        * loader/ImageLoader.cpp:
+        (WebCore::ImageLoader::updateFromElement): Call setClient() after
+        dispatching beforeload, since setClient() will dispatch the load event
+        if the image is cached.
+
 2011-09-15  Anders Carlsson  <andersca@apple.com>
 

trunk/Source/WebCore/loader/ImageLoader.cpp

@@ -203 +203 @@
 
         if (newImage) {
-            newImage->addClient(this);
             if (!m_element->document()->hasListenerType(Document::BEFORELOAD_LISTENER))
                 dispatchPendingBeforeLoadEvent();
             else
                 beforeLoadEventSender().dispatchEventSoon(this);
+
+            // If newImage is cached, addClient() will result in the load event
+            // being queued to fire. Ensure this happens after beforeload is
+            // dispatched.
+            newImage->addClient(this);
         }
         if (oldImage)