Gracefully handle <meta http-equiv name content> elements.

Source/core/html/HTMLMetaElement-in.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 433 matching lines @@
 {
     if (!inDocument())
         return;
 
     // All below situations require a content attribute (which can be the empty string).
     const AtomicString& contentValue = fastGetAttribute(contentAttr);
     if (contentValue.isNull())
         return;
 
     const AtomicString& nameValue = fastGetAttribute(nameAttr);
-    if (nameValue.isNull()) {
-        // Get the document to process the tag, but only if we're actually part of DOM
-        // tree (changing a meta tag while it's not in the tree shouldn't have any effect
-        // on the document).
-        const AtomicString& httpEquivValue = fastGetAttribute(http_equivAttr);
-        if (!httpEquivValue.isNull())
-            document().processHttpEquiv(httpEquivValue, contentValue);
-        return;
+    if (!nameValue.isEmpty()) {
+        if (equalIgnoringCase(nameValue, "viewport"))
+            processViewportContentAttribute(contentValue, ViewportDescription::ViewportMeta);
+        else if (equalIgnoringCase(nameValue, "referrer"))
+            document().processReferrerPolicy(contentValue);
+        else if (equalIgnoringCase(nameValue, "handheldfriendly") && equalIgnoringCase(contentValue, "true"))
+            processViewportContentAttribute("width=device-width", ViewportDescription::HandheldFriendlyMeta);
+        else if (equalIgnoringCase(nameValue, "mobileoptimized"))
+            processViewportContentAttribute("width=device-width, initial-scale=1", ViewportDescription::MobileOptimizedMeta);
     }
 
-    if (equalIgnoringCase(nameValue, "viewport"))
-        processViewportContentAttribute(contentValue, ViewportDescription::ViewportMeta);
-    else if (equalIgnoringCase(nameValue, "referrer"))
-        document().processReferrerPolicy(contentValue);
-    else if (equalIgnoringCase(nameValue, "handheldfriendly") && equalIgnoringCase(contentValue, "true"))
-        processViewportContentAttribute("width=device-width", ViewportDescription::HandheldFriendlyMeta);
-    else if (equalIgnoringCase(nameValue, "mobileoptimized"))
-        processViewportContentAttribute("width=device-width, initial-scale=1", ViewportDescription::MobileOptimizedMeta);
+    // Get the document to process the tag, but only if we're actually part of DOM
+    // tree (changing a meta tag while it's not in the tree shouldn't have any effect
+    // on the document).
+    const AtomicString& httpEquivValue = fastGetAttribute(http_equivAttr);
+    if (!httpEquivValue.isEmpty())
+        document().processHttpEquiv(httpEquivValue, contentValue);
 }
 
 const AtomicString& HTMLMetaElement::content() const
 {
     return getAttribute(contentAttr);
 }
 
 const AtomicString& HTMLMetaElement::httpEquiv() const
 {
     return getAttribute(http_equivAttr);
 }
 
 const AtomicString& HTMLMetaElement::name() const
 {
     return getNameAttribute();
 }
 
 }