2011-04-05 James Simonsen <simonjam@chromium.org>

        Reviewed by Adam Barth.

        Stop preload scanning CSS when it's impossible to have another @import.
        https://bugs.webkit.org/show_bug.cgi?id=57664

        * fast/preloader/style-expected.txt:
        * fast/preloader/style.html: Updated to test invalid @import statements.
2011-04-05  James Simonsen  <simonjam@chromium.org>

        Reviewed by Adam Barth.

        Stop preload scanning CSS when it&apos;s impossible to have another @import.
        https://bugs.webkit.org/show_bug.cgi?id=57664

        @import statements are only allowed at the beginning of a CSS file.
        Only comments or @charset can precede them. After seeing anything else,
        abort early so that we:
        - don't have to parse the rest of the CSS.
        - don't preload something that the regular parser won't load.

        * html/parser/CSSPreloadScanner.cpp:
        (WebCore::CSSPreloadScanner::scan): Terminate early if we're done with @imports.
        (WebCore::CSSPreloadScanner::tokenize): Terminate early if we see a {} or any style rule.
        (WebCore::CSSPreloadScanner::emitRule): Only @charset or @import are allowed to precede @import.
        * html/parser/CSSPreloadScanner.h: Add DoneParsingImportRules state.

git-svn-id: svn://svn.chromium.org/blink/trunk@82916 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/ChangeLog

+2011-04-05  James Simonsen  <simonjam@chromium.org>
+
+        Reviewed by Adam Barth.
+
+        Stop preload scanning CSS when it&apos;s impossible to have another @import.
+        https://bugs.webkit.org/show_bug.cgi?id=57664
+
+        * fast/preloader/style-expected.txt:
+        * fast/preloader/style.html: Updated to test invalid @import statements.
+
 2011-04-05  Kent Tamura  <tkent@chromium.org>
 
         Update a test affected by the behavior change of r82908.

third_party/WebKit/LayoutTests/fast/preloader/style-expected.txt

@@ -2,6 +2,18 @@ style1.css has MIME type text/css
 This test requires DumpRenderTree to see the log of what resources are loaded.
 
 <style>
+@charset "ascii";
+/* */
 @import "resources/style1.css";
+em {
+    @import "resources/fail.css";
+}
+@import "resources/fail.css";
+</style>
+<style>
+@media print {
+    @import "resources/fail.css";
+}
+@import "resources/fail.css";
 </style>
 

third_party/WebKit/LayoutTests/fast/preloader/style.html

@@ -9,5 +9,17 @@ This test requires DumpRenderTree to see the log of what resources are loaded.
 <script src=resources/non-existant.js></script>
 <script>document.write("<plaintext>");</script>
 <style>
+@charset "ascii";
+/* */
 @import "resources/style1.css";
+em {
+    @import "resources/fail.css";
+}
+@import "resources/fail.css";
+</style>
+<style>
+@media print {
+    @import "resources/fail.css";
+}
+@import "resources/fail.css";
 </style>

third_party/WebKit/Source/WebCore/ChangeLog

+2011-04-05  James Simonsen  <simonjam@chromium.org>
+
+        Reviewed by Adam Barth.
+
+        Stop preload scanning CSS when it&apos;s impossible to have another @import.
+        https://bugs.webkit.org/show_bug.cgi?id=57664
+
+        @import statements are only allowed at the beginning of a CSS file.
+        Only comments or @charset can precede them. After seeing anything else,
+        abort early so that we:
+        - don't have to parse the rest of the CSS.
+        - don't preload something that the regular parser won't load.
+
+        * html/parser/CSSPreloadScanner.cpp:
+        (WebCore::CSSPreloadScanner::scan): Terminate early if we're done with @imports.
+        (WebCore::CSSPreloadScanner::tokenize): Terminate early if we see a {} or any style rule.
+        (WebCore::CSSPreloadScanner::emitRule): Only @charset or @import are allowed to precede @import.
+        * html/parser/CSSPreloadScanner.h: Add DoneParsingImportRules state.
+
 2011-04-05  Takayoshi Kochi <kochi@chromium.org>
 
         Reviewed by Tony Chang.

third_party/WebKit/Source/WebCore/html/parser/CSSPreloadScanner.cpp

@@ -54,7 +54,7 @@ void CSSPreloadScanner::scan(const HTMLToken& token, bool scanningBody)
     m_scanningBody = scanningBody;
 
     const HTMLToken::DataVector& characters = token.characters();
-    for (HTMLToken::DataVector::const_iterator iter = characters.begin(); iter != characters.end(); ++iter)
+    for (HTMLToken::DataVector::const_iterator iter = characters.begin(); iter != characters.end() && m_state != DoneParsingImportRules; ++iter)
         tokenize(*iter);
 }
 
@@ -64,10 +64,14 @@ inline void CSSPreloadScanner::tokenize(UChar c)
     // Searching for other types of resources is probably low payoff.
     switch (m_state) {
     case Initial:
+        if (isHTMLSpace(c))
+            break;
         if (c == '@')
             m_state = RuleStart;
         else if (c == '/')
             m_state = MaybeComment;
+        else
+            m_state = DoneParsingImportRules;
         break;
     case MaybeComment:
         if (c == '*')
@@ -80,10 +84,10 @@ inline void CSSPreloadScanner::tokenize(UChar c)
             m_state = MaybeCommentEnd;
         break;
     case MaybeCommentEnd:
+        if (c == '*')
+            break;
         if (c == '/')
             m_state = Initial;
-        else if (c == '*')
-            ;
         else
             m_state = Comment;
         break;
@@ -106,9 +110,11 @@ inline void CSSPreloadScanner::tokenize(UChar c)
         break;
     case AfterRule:
         if (isHTMLSpace(c))
-            ;
-        else if (c == ';')
+            break;
+        if (c == ';')
             m_state = Initial;
+        else if (c == '{')
+            m_state = DoneParsingImportRules;
         else {
             m_state = RuleValue;
             m_ruleValue.append(c);
@@ -117,23 +123,26 @@ inline void CSSPreloadScanner::tokenize(UChar c)
     case RuleValue:
         if (isHTMLSpace(c))
             m_state = AfterRuleValue;
-        else if (c == ';') {
+        else if (c == ';')
             emitRule();
-            m_state = Initial;
-        } else 
+        else
             m_ruleValue.append(c);
         break;
     case AfterRuleValue:
         if (isHTMLSpace(c))
-            ;
-        else if (c == ';') {
+            break;
+        if (c == ';')
             emitRule();
-            m_state = Initial;
-        } else {
+        else if (c == '{')
+            m_state = DoneParsingImportRules;
+        else {
             // FIXME: media rules
             m_state = Initial;
         }
         break;
+    case DoneParsingImportRules:
+        ASSERT_NOT_REACHED();
+        break;
     }
 }
 
@@ -187,7 +196,11 @@ void CSSPreloadScanner::emitRule()
         String value = parseCSSStringOrURL(m_ruleValue.data(), m_ruleValue.size());
         if (!value.isEmpty())
             m_document->cachedResourceLoader()->preload(CachedResource::CSSStyleSheet, value, String(), m_scanningBody);
-    }
+        m_state = Initial;
+    } else if (equalIgnoringCase("charset", m_rule.data(), m_rule.size()))
+        m_state = Initial;
+    else
+        m_state = DoneParsingImportRules;
     m_rule.clear();
     m_ruleValue.clear();
 }

third_party/WebKit/Source/WebCore/html/parser/CSSPreloadScanner.h

@@ -53,7 +53,8 @@ private:
         Rule,
         AfterRule,
         RuleValue,
-        AfterRuleValue
+        AfterRuleValue,
+        DoneParsingImportRules,
     };
 
     inline void tokenize(UChar c);