Changeset 202127 in webkit

Timestamp:

Jun 16, 2016 10:10:38 AM (8 years ago)

Author:

mmaxfield@apple.com

Message:

Sporadic crash in HashTableAddResult following CSSValuePool::createFontFamilyValue
​https://bugs.webkit.org/show_bug.cgi?id=158297

Reviewed by Darin Adler.

Source/WebCore:

In an effort to reduce the flash of unstyled content, we force all elements
to have display: none during an external stylesheet load. We do this by
ignoring the CSS cascade and forcing all elements to have a placeholder style
which hardcodes display: none. (This is necessary to make elements created by
script during the stylesheet load not flash.)

This style is exposed to web content via getComputedStyle(), which means it
needs to maintain the invariant that font-families can never be null strings.
We enforce this by forcing the font-family to be the standard font name.

Test: fast/text/placeholder-renderstyle-null-font.html

• style/StyleTreeResolver.cpp:

(WebCore::Style::ensurePlaceholderStyle):

LayoutTests:

• fast/text/placeholder-renderstyle-null-font-expected.txt: Added.
• fast/text/placeholder-renderstyle-null-font.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/text/placeholder-renderstyle-null-font-expected.txt (added)
• LayoutTests/fast/text/placeholder-renderstyle-null-font.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/style/StyleTreeResolver.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2016-06-16  Myles C. Maxfield  <mmaxfield@apple.com>
+
+        Sporadic crash in HashTableAddResult following CSSValuePool::createFontFamilyValue
+        https://bugs.webkit.org/show_bug.cgi?id=158297
+
+        Reviewed by Darin Adler.
+
+        * fast/text/placeholder-renderstyle-null-font-expected.txt: Added.
+        * fast/text/placeholder-renderstyle-null-font.html: Added.
+
 2016-06-15  Keith Miller  <keith_miller@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2016-06-16  Myles C. Maxfield  <mmaxfield@apple.com>
+
+        Sporadic crash in HashTableAddResult following CSSValuePool::createFontFamilyValue
+        https://bugs.webkit.org/show_bug.cgi?id=158297
+
+        Reviewed by Darin Adler.
+
+        In an effort to reduce the flash of unstyled content, we force all elements
+        to have display: none during an external stylesheet load. We do this by
+        ignoring the CSS cascade and forcing all elements to have a placeholder style
+        which hardcodes display: none. (This is necessary to make elements created by
+        script during the stylesheet load not flash.)
+
+        This style is exposed to web content via getComputedStyle(), which means it
+        needs to maintain the invariant that font-families can never be null strings.
+        We enforce this by forcing the font-family to be the standard font name.
+
+        Test: fast/text/placeholder-renderstyle-null-font.html
+
+        * style/StyleTreeResolver.cpp:
+        (WebCore::Style::ensurePlaceholderStyle):
+
 2016-06-16  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebCore/style/StyleTreeResolver.cpp

@@ -44 +44 @@
 #include "Settings.h"
 #include "ShadowRoot.h"
+#include "StyleFontSizeFunctions.h"
 #include "StyleResolver.h"
 #include "Text.h"
@@ -64 +65 @@
     placeholderStyle->setDisplay(NONE);
     placeholderStyle->setIsPlaceholderStyle();
+
+    FontCascadeDescription fontDescription;
+    fontDescription.setOneFamily(standardFamily);
+    fontDescription.setKeywordSizeFromIdentifier(CSSValueMedium);
+    float size = Style::fontSizeForKeyword(CSSValueMedium, false, document);
+    fontDescription.setSpecifiedSize(size);
+    fontDescription.setComputedSize(size);
+    placeholderStyle->setFontDescription(fontDescription);
+
     placeholderStyle->fontCascade().update(&document.fontSelector());
 }