<!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>[195705] 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/195705">195705</a></dd>
<dt>Author</dt> <dd>n_wang@apple.com</dd>
<dt>Date</dt> <dd>2016-01-27 16:17:20 -0800 (Wed, 27 Jan 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>AX: Crash in AccessibilityTableColumn::headerObject
https://bugs.webkit.org/show_bug.cgi?id=153553
<rdar://problem/23196278>
Reviewed by Chris Fleizach.
Webkit was crashing sometimes when we asked for column headers of a table.
The columns vector of the table was reset during the iteration when we
were asking for the headerObject of each column. The column's addChildren()
function calls elementRect() for each child cell and that sometimes causes
the parent table to reset its children.
Fixed it by caching the columns vector and moving out the elementRect() logic
from AccessibilityTalbeColumn::addChildren().
* accessibility/AccessibilityTable.cpp:
(WebCore::AccessibilityTable::columnHeaders):
(WebCore::AccessibilityTable::rowHeaders):
* accessibility/AccessibilityTableColumn.cpp:
(WebCore::AccessibilityTableColumn::elementRect):
(WebCore::AccessibilityTableColumn::headerObject):
(WebCore::AccessibilityTableColumn::addChildren):
* accessibility/AccessibilityTableColumn.h:</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceWebCoreChangeLog">trunk/Source/WebCore/ChangeLog</a></li>
<li><a href="#trunkSourceWebCoreaccessibilityAccessibilityTablecpp">trunk/Source/WebCore/accessibility/AccessibilityTable.cpp</a></li>
<li><a href="#trunkSourceWebCoreaccessibilityAccessibilityTableColumncpp">trunk/Source/WebCore/accessibility/AccessibilityTableColumn.cpp</a></li>
<li><a href="#trunkSourceWebCoreaccessibilityAccessibilityTableColumnh">trunk/Source/WebCore/accessibility/AccessibilityTableColumn.h</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceWebCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/ChangeLog (195704 => 195705)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/ChangeLog 2016-01-28 00:16:52 UTC (rev 195704)
+++ trunk/Source/WebCore/ChangeLog 2016-01-28 00:17:20 UTC (rev 195705)
</span><span class="lines">@@ -1,3 +1,28 @@
</span><ins>+2016-01-27 Nan Wang <n_wang@apple.com>
+
+ AX: Crash in AccessibilityTableColumn::headerObject
+ https://bugs.webkit.org/show_bug.cgi?id=153553
+ <rdar://problem/23196278>
+
+ Reviewed by Chris Fleizach.
+
+ Webkit was crashing sometimes when we asked for column headers of a table.
+ The columns vector of the table was reset during the iteration when we
+ were asking for the headerObject of each column. The column's addChildren()
+ function calls elementRect() for each child cell and that sometimes causes
+ the parent table to reset its children.
+ Fixed it by caching the columns vector and moving out the elementRect() logic
+ from AccessibilityTalbeColumn::addChildren().
+
+ * accessibility/AccessibilityTable.cpp:
+ (WebCore::AccessibilityTable::columnHeaders):
+ (WebCore::AccessibilityTable::rowHeaders):
+ * accessibility/AccessibilityTableColumn.cpp:
+ (WebCore::AccessibilityTableColumn::elementRect):
+ (WebCore::AccessibilityTableColumn::headerObject):
+ (WebCore::AccessibilityTableColumn::addChildren):
+ * accessibility/AccessibilityTableColumn.h:
+
</ins><span class="cx"> 2016-01-27 Chris Dumez <cdumez@apple.com>
</span><span class="cx">
</span><span class="cx"> Settings a reflected DOMString attribute to null should set it to the "null" string rather than the empty string
</span></span></pre></div>
<a id="trunkSourceWebCoreaccessibilityAccessibilityTablecpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/accessibility/AccessibilityTable.cpp (195704 => 195705)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/accessibility/AccessibilityTable.cpp 2016-01-28 00:16:52 UTC (rev 195704)
+++ trunk/Source/WebCore/accessibility/AccessibilityTable.cpp 2016-01-28 00:17:20 UTC (rev 195705)
</span><span class="lines">@@ -502,7 +502,10 @@
</span><span class="cx">
</span><span class="cx"> updateChildrenIfNecessary();
</span><span class="cx">
</span><del>- for (const auto& column : m_columns) {
</del><ins>+ // Sometimes m_columns can be reset during the iteration, we cache it here to be safe.
+ AccessibilityChildrenVector columnsCopy = m_columns;
+
+ for (const auto& column : columnsCopy) {
</ins><span class="cx"> if (AccessibilityObject* header = downcast<AccessibilityTableColumn>(*column).headerObject())
</span><span class="cx"> headers.append(header);
</span><span class="cx"> }
</span><span class="lines">@@ -515,7 +518,10 @@
</span><span class="cx">
</span><span class="cx"> updateChildrenIfNecessary();
</span><span class="cx">
</span><del>- for (const auto& row : m_rows) {
</del><ins>+ // Sometimes m_rows can be reset during the iteration, we cache it here to be safe.
+ AccessibilityChildrenVector rowsCopy = m_rows;
+
+ for (const auto& row : rowsCopy) {
</ins><span class="cx"> if (AccessibilityObject* header = downcast<AccessibilityTableRow>(*row).headerObject())
</span><span class="cx"> headers.append(header);
</span><span class="cx"> }
</span></span></pre></div>
<a id="trunkSourceWebCoreaccessibilityAccessibilityTableColumncpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/accessibility/AccessibilityTableColumn.cpp (195704 => 195705)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/accessibility/AccessibilityTableColumn.cpp 2016-01-28 00:16:52 UTC (rev 195704)
+++ trunk/Source/WebCore/accessibility/AccessibilityTableColumn.cpp 2016-01-28 00:17:20 UTC (rev 195705)
</span><span class="lines">@@ -63,8 +63,14 @@
</span><span class="cx">
</span><span class="cx"> LayoutRect AccessibilityTableColumn::elementRect() const
</span><span class="cx"> {
</span><del>- // this will be filled in when addChildren is called
- return m_columnRect;
</del><ins>+ // This used to be cached during the call to addChildren(), but calling elementRect()
+ // can invalidate elements, so its better to ask for this on demand.
+ LayoutRect columnRect;
+ AccessibilityChildrenVector childrenCopy = m_children;
+ for (const auto& cell : childrenCopy)
+ columnRect.unite(cell->elementRect());
+
+ return columnRect;
</ins><span class="cx"> }
</span><span class="cx">
</span><span class="cx"> AccessibilityObject* AccessibilityTableColumn::headerObject()
</span><span class="lines">@@ -191,7 +197,6 @@
</span><span class="cx"> continue;
</span><span class="cx">
</span><span class="cx"> m_children.append(cell);
</span><del>- m_columnRect.unite(cell->elementRect());
</del><span class="cx"> }
</span><span class="cx"> }
</span><span class="cx">
</span></span></pre></div>
<a id="trunkSourceWebCoreaccessibilityAccessibilityTableColumnh"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/accessibility/AccessibilityTableColumn.h (195704 => 195705)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/accessibility/AccessibilityTableColumn.h 2016-01-28 00:16:52 UTC (rev 195704)
+++ trunk/Source/WebCore/accessibility/AccessibilityTableColumn.h 2016-01-28 00:17:20 UTC (rev 195705)
</span><span class="lines">@@ -62,7 +62,6 @@
</span><span class="cx"> virtual bool isTableColumn() const override { return true; }
</span><span class="cx">
</span><span class="cx"> unsigned m_columnIndex;
</span><del>- LayoutRect m_columnRect;
</del><span class="cx"> };
</span><span class="cx">
</span><span class="cx"> } // namespace WebCore
</span></span></pre>
</div>
</div>
</body>
</html>