Escape "--" in the page URL at page serialization

third_party/WebKit/Source/core/page/PageSerializer.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 235 matching lines @@
     , m_rewriteFolder(rewriteFolder)
 {
 }
 
 void LinkChangeSerializerMarkupAccumulator::appendElement(StringBuilder& result, Element& element, Namespaces* namespaces)
 {
     if (element.hasTagName(HTMLNames::htmlTag)) {
         // Add MOTW (Mark of the Web) declaration before html tag.
         // See http://msdn2.microsoft.com/en-us/library/ms537628(VS.85).aspx.
         result.append('\n');
-        MarkupFormatter::appendComment(result, String::format(" saved from url=(%04d)%s ",
-            static_cast<int>(document().url().string().utf8().length()),
-            document().url().string().utf8().data()));
+        MarkupFormatter::appendComment(result, PageSerializer::markOfTheWebDeclaration(document().url()));
         result.append('\n');
     }
 
     if (element.hasTagName(HTMLNames::baseTag)) {
         // TODO(tiger): Refactor MarkupAccumulator so it is easier to append an element like this, without special cases for XHTML
         // Append a new base tag declaration.
         result.appendLiteral("<base href=\".\"");
         if (!document().baseTarget().isEmpty()) {
             result.appendLiteral(" target=\"");
             MarkupFormatter::appendAttributeValue(result, document().baseTarget(), document().isHTMLDocument());
@@ skipping 301 matching lines @@
     m_blankFrameURLs.add(frame, fakeURL);
 
     return fakeURL;
 }
 
 PageSerializer::Delegate* PageSerializer::delegate()
 {
     return m_delegate.get();
 }
 
+// Returns MOTW (Mark of the Web) declaration before html tag which is in
+// HTML comment, e.g. "<!-- saved from url=(%04d)%s -->"
+// See http://msdn2.microsoft.com/en-us/library/ms537628(VS.85).aspx.
+String PageSerializer::markOfTheWebDeclaration(const KURL& url)
+{
+    StringBuilder builder;
+    bool emitsMinus = false;
+    CString orignalUrl = url.string().ascii();
+    for (const char* string = orignalUrl.data(); *string; ++string) {
+        const char ch = *string;
+        if (ch == '-' && emitsMinus) {
+            builder.append("%2D");
+            emitsMinus = false;
+            continue;
+        }
+        emitsMinus = ch == '-';
+        builder.append(ch);
+    }
+    CString escapedUrl = builder.toString().ascii();
+    return String::format("saved from url=(%04d)%s", static_cast<int>(escapedUrl.length()), escapedUrl.data());
+}
+
 } // namespace blink