Changeset 57299 in webkit

Timestamp:

Apr 8, 2010 3:37:37 PM (14 years ago)

Author:

hyatt@apple.com

Message:

Followup optimization to bug 24300, don't leak history info via CSS :visited. If a Web
site uses document colors that are the same for link and vlink in HTML and also doesn't
specify any :link or :visited rules, then don't waste time resolving visited styles.

Reviewed by Oliver Hunt.

There is a further optimization that could be done to detect when :link and :visited are
used together in the same rule to specify a color, and this is how most sites turn off
visited link colors, but this fix doesn't address that. It just restores the optimization
that existed prior to the patch in 24300 landing.

• css/CSSGrammar.y:
• css/CSSStyleSelector.cpp:

(WebCore::CSSStyleSelector::styleForElement):

• dom/Document.cpp:

(WebCore::Document::Document):

• dom/Document.h:

(WebCore::Document::usesLinkRules):
(WebCore::Document::setUsesLinkRules):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• css/CSSGrammar.y (modified) (1 diff)
• css/CSSStyleSelector.cpp (modified) (1 diff)
• dom/Document.cpp (modified) (1 diff)
• dom/Document.h (modified) (2 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-04-08  David Hyatt  <hyatt@apple.com>
+
+        Reviewed by Oliver Hunt.
+
+        Followup optimization to bug 24300, don't leak history info via CSS :visited.  If a Web
+        site uses document colors that are the same for link and vlink in HTML and also doesn't
+        specify any :link or :visited rules, then don't waste time resolving visited styles.
+
+        There is a further optimization that could be done to detect when :link and :visited are
+        used together in the same rule to specify a color, and this is how most sites turn off
+        visited link colors, but this fix doesn't address that.  It just restores the optimization
+        that existed prior to the patch in 24300 landing.
+
+        * css/CSSGrammar.y:
+        * css/CSSStyleSelector.cpp:
+        (WebCore::CSSStyleSelector::styleForElement):
+        * dom/Document.cpp:
+        (WebCore::Document::Document):
+        * dom/Document.h:
+        (WebCore::Document::usesLinkRules):
+        (WebCore::Document::setUsesLinkRules):
+
 2010-04-08  David Hyatt  <hyatt@apple.com>
 

trunk/WebCore/css/CSSGrammar.y

@@ -1096 +1096 @@
             if (Document* doc = p->document())
                 doc->setUsesBeforeAfterRules(true);
+        } else if (type == CSSSelector::PseudoLink || type == CSSSelector::PseudoVisited) {
+            CSSParser* p = static_cast<CSSParser*>(parser);
+            if (Document* doc = p->document())
+                doc->setUsesLinkRules(true);
         }
     }

trunk/WebCore/css/CSSStyleSelector.cpp

@@ -1319 +1319 @@
 
     // Compute our style allowing :visited to match.
-    if (!matchVisitedRules && m_style->insideLink()) {
+    if (!matchVisitedRules && m_style->insideLink() && e->document()->usesLinkRules()) {
         // Fetch our parent style.
         RenderStyle* parentStyle = m_parentStyle;

trunk/WebCore/dom/Document.cpp

@@ -429 +429 @@
     m_usesBeforeAfterRules = false;
     m_usesRemUnits = false;
+    m_usesLinkRules = false;
 
     m_gotoAnchorNeededAfterStylesheetsLoad = false;

trunk/WebCore/dom/Document.h

@@ -441 +441 @@
     bool usesRemUnits() const { return m_usesRemUnits; }
     void setUsesRemUnits(bool b) { m_usesRemUnits = b; }
+    bool usesLinkRules() const { return linkColor() != visitedLinkColor() || m_usesLinkRules; }
+    void setUsesLinkRules(bool b) { m_usesLinkRules = b; }
 
     // Machinery for saving and restoring state when you leave and then go back to a page.
@@ -1102 +1104 @@
     bool m_usesBeforeAfterRules;
     bool m_usesRemUnits;
+    bool m_usesLinkRules;
     bool m_gotoAnchorNeededAfterStylesheetsLoad;
     bool m_isDNSPrefetchEnabled;