Changeset 195606 in webkit

Timestamp:

Jan 26, 2016 12:07:07 PM (8 years ago)

Author:

hyatt@apple.com

Message:

Speculative fixes for crashing in viewportChangeAffectedPicture
​https://bugs.webkit.org/show_bug.cgi?id=153450

Reviewed by Dean Jackson.

Don't attach any conditions to the removal of a picture element from
the document's HashSet. This ensures that if the condition is ever
wrong for any reason, we'll still remove the picture element on
destruction.

Fix the media query evaluation to match the other evaluations (used by
the preload scanner and HTMLImageElement). This includes using the
document element's computed style instead of our own and also null
checking the document element first. This is the likely cause of the
crashes.

• html/HTMLPictureElement.cpp:

(WebCore::HTMLPictureElement::~HTMLPictureElement):
(WebCore::HTMLPictureElement::didMoveToNewDocument):
(WebCore::HTMLPictureElement::viewportChangeAffectedPicture):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• html/HTMLPictureElement.cpp (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2016-01-25  Dave Hyatt  <hyatt@apple.com>
+
+        Speculative fixes for crashing in viewportChangeAffectedPicture
+        https://bugs.webkit.org/show_bug.cgi?id=153450
+
+        Reviewed by Dean Jackson.
+
+        Don't attach any conditions to the removal of a picture element from
+        the document's HashSet. This ensures that if the condition is ever
+        wrong for any reason, we'll still remove the picture element on
+        destruction.
+
+        Fix the media query evaluation to match the other evaluations (used by
+        the preload scanner and HTMLImageElement). This includes using the
+        document element's computed style instead of our own and also null
+        checking the document element first. This is the likely cause of the
+        crashes.
+
+        * html/HTMLPictureElement.cpp:
+        (WebCore::HTMLPictureElement::~HTMLPictureElement):
+        (WebCore::HTMLPictureElement::didMoveToNewDocument):
+        (WebCore::HTMLPictureElement::viewportChangeAffectedPicture):
+
 2016-01-26  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebCore/html/HTMLPictureElement.cpp

@@ -40 +40 @@
 HTMLPictureElement::~HTMLPictureElement()
 {
-    if (hasViewportDependentResults())
-        document().removeViewportDependentPicture(*this);
+    document().removeViewportDependentPicture(*this);
 }
 
 void HTMLPictureElement::didMoveToNewDocument(Document* oldDocument)
 {
-    if (hasViewportDependentResults() && oldDocument)
+    if (oldDocument)
         oldDocument->removeViewportDependentPicture(*this);
     HTMLElement::didMoveToNewDocument(oldDocument);
@@ -65 +64 @@
 bool HTMLPictureElement::viewportChangeAffectedPicture()
 {
-    MediaQueryEvaluator evaluator(document().printing() ? "print" : "screen", document().frame(), computedStyle());
+    MediaQueryEvaluator evaluator(document().printing() ? "print" : "screen", document().frame(), document().documentElement() ? document().documentElement()->computedStyle() : nullptr);
     unsigned numResults = m_viewportDependentMediaQueryResults.size();
     for (unsigned i = 0; i < numResults; i++) {