Changeset 211957 in webkit

Timestamp:

Feb 9, 2017 8:32:13 AM (7 years ago)

Author:

Antti Koivisto

Message:

Nullptr crash under styleForFirstLetter
​https://bugs.webkit.org/show_bug.cgi?id=167756
rdar://problem/30029354

Reviewed by Zalan Bujtas.

Don't know how we get here. Paper over the crash.

• rendering/RenderBlock.cpp:

(WebCore::styleForFirstLetter):

Use parent first line style if we compute null style for the first letter renderer.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderBlock.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2017-02-09  Antti Koivisto  <antti@apple.com>
+
+        Nullptr crash under styleForFirstLetter
+        https://bugs.webkit.org/show_bug.cgi?id=167756
+        rdar://problem/30029354
+
+        Reviewed by Zalan Bujtas.
+
+        Don't know how we get here. Paper over the crash.
+
+        * rendering/RenderBlock.cpp:
+        (WebCore::styleForFirstLetter):
+
+            Use parent first line style if we compute null style for the first letter renderer.
+
 2017-02-09  Antoine Quint  <graouts@apple.com>
 

trunk/Source/WebCore/rendering/RenderBlock.cpp

@@ -3017 +3017 @@
 static RenderStyle styleForFirstLetter(const RenderElement& firstLetterBlock, const RenderObject& firstLetterContainer)
 {
-    auto firstLetterStyle = RenderStyle::clone(*firstLetterBlock.getCachedPseudoStyle(FIRST_LETTER, &firstLetterContainer.firstLineStyle()));
+    auto* containerFirstLetterStyle = firstLetterBlock.getCachedPseudoStyle(FIRST_LETTER, &firstLetterContainer.firstLineStyle());
+    // FIXME: There appears to be some path where we have a first letter renderer without first letter style.
+    ASSERT(containerFirstLetterStyle);
+    auto firstLetterStyle = RenderStyle::clone(containerFirstLetterStyle ? *containerFirstLetterStyle : firstLetterContainer.firstLineStyle());
 
     // If we have an initial letter drop that is >= 1, then we need to force floating to be on.