<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[199245] trunk/Source/WebCore</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/199245">199245</a></dd>
<dt>Author</dt> <dd>bfulgham@apple.com</dd>
<dt>Date</dt> <dd>2016-04-08 13:46:25 -0700 (Fri, 08 Apr 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>[WK1] Wheel event callback removing the window causes crash in WebCore
https://bugs.webkit.org/show_bug.cgi?id=156409
<rdar://problem/25631267>
Reviewed by Simon Fraser.
Null check the Widget before using it, since the iframe may have been removed
from its parent document inside the event handler.
This is the WK1 fix for https://bugs.webkit.org/show_bug.cgi?id=150871.
Tested by fast/events/wheel-event-destroys-frame.html
* page/EventHandler.cpp:
(WebCore::widgetForElement): Added.
(WebCore::EventHandler::handleWheelEvent): Use new helper function to
clean up the code, and allow us to check that the Widget has not been
destroyed during the event handler.</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceWebCoreChangeLog">trunk/Source/WebCore/ChangeLog</a></li>
<li><a href="#trunkSourceWebCorepageEventHandlercpp">trunk/Source/WebCore/page/EventHandler.cpp</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceWebCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/ChangeLog (199244 => 199245)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/ChangeLog 2016-04-08 20:19:26 UTC (rev 199244)
+++ trunk/Source/WebCore/ChangeLog 2016-04-08 20:46:25 UTC (rev 199245)
</span><span class="lines">@@ -1,3 +1,24 @@
</span><ins>+2016-04-08 Brent Fulgham <bfulgham@apple.com>
+
+ [WK1] Wheel event callback removing the window causes crash in WebCore
+ https://bugs.webkit.org/show_bug.cgi?id=156409
+ <rdar://problem/25631267>
+
+ Reviewed by Simon Fraser.
+
+ Null check the Widget before using it, since the iframe may have been removed
+ from its parent document inside the event handler.
+
+ This is the WK1 fix for https://bugs.webkit.org/show_bug.cgi?id=150871.
+
+ Tested by fast/events/wheel-event-destroys-frame.html
+
+ * page/EventHandler.cpp:
+ (WebCore::widgetForElement): Added.
+ (WebCore::EventHandler::handleWheelEvent): Use new helper function to
+ clean up the code, and allow us to check that the Widget has not been
+ destroyed during the event handler.
+
</ins><span class="cx"> 2016-04-08 Said Abou-Hallawa <sabouhallawa@apple,com>
</span><span class="cx">
</span><span class="cx"> Timing attack on SVG feComposite filter circumvents same-origin policy
</span></span></pre></div>
<a id="trunkSourceWebCorepageEventHandlercpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/page/EventHandler.cpp (199244 => 199245)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/page/EventHandler.cpp 2016-04-08 20:19:26 UTC (rev 199244)
+++ trunk/Source/WebCore/page/EventHandler.cpp 2016-04-08 20:46:25 UTC (rev 199245)
</span><span class="lines">@@ -2610,6 +2610,18 @@
</span><span class="cx"> }
</span><span class="cx"> #endif
</span><span class="cx">
</span><ins>+static Widget* widgetForElement(const Element& element)
+{
+ RenderElement* target = element.renderer();
+ if (!target)
+ return nullptr;
+
+ if (!is<RenderWidget>(target))
+ return nullptr;
+
+ return downcast<RenderWidget>(*target).widget();
+}
+
</ins><span class="cx"> bool EventHandler::handleWheelEvent(const PlatformWheelEvent& event)
</span><span class="cx"> {
</span><span class="cx"> RenderView* renderView = m_frame.contentRenderer();
</span><span class="lines">@@ -2650,18 +2662,21 @@
</span><span class="cx">
</span><span class="cx"> if (element) {
</span><span class="cx"> if (isOverWidget) {
</span><del>- RenderElement* target = element->renderer();
- if (is<RenderWidget>(target)) {
- Widget* widget = downcast<RenderWidget>(*target).widget();
- if (widget && passWheelEventToWidget(event, *widget)) {
- m_isHandlingWheelEvent = false;
- if (scrollableArea)
- scrollableArea->setScrolledProgrammatically(false);
- platformNotifyIfEndGesture(adjustedEvent, scrollableArea);
- if (!widget->platformWidget())
- return true;
- return platformCompletePlatformWidgetWheelEvent(event, *widget, scrollableContainer.get());
- }
</del><ins>+ Widget* widget = widgetForElement(*element);
+ if (widget && passWheelEventToWidget(event, *widget)) {
+ m_isHandlingWheelEvent = false;
+
+ // We do another check on the widget because the event handler can run JS which results in the frame getting destroyed.
+ Widget* widget = widgetForElement(*element);
+ if (!widget)
+ return false;
+
+ if (scrollableArea)
+ scrollableArea->setScrolledProgrammatically(false);
+ platformNotifyIfEndGesture(adjustedEvent, scrollableArea);
+ if (!widget->platformWidget())
+ return true;
+ return platformCompletePlatformWidgetWheelEvent(event, *widget, scrollableContainer.get());
</ins><span class="cx"> }
</span><span class="cx"> }
</span><span class="cx">
</span></span></pre>
</div>
</div>
</body>
</html>