WebVTTParser's identifier buffering can ignore subsequent lines

https://bugs.webkit.org/show_bug.cgi?id=118483

Patch by Brendan Long <b.long@cablelabs.com> on 2013-07-24
Reviewed by Eric Carlson.

No new tests since this bug can't be reproduced in layout tests.

* html/track/WebVTTParser.cpp:
(WebCore::WebVTTParser::parseBytes): Only buffer the identifier if we haven't read an entire line.

Canonical link: https://commits.webkit.org/136877@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@153086 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,15 @@
+2013-07-24  Brendan Long  <b.long@cablelabs.com>
+
+        WebVTTParser's identifier buffering can ignore subsequent lines
+        https://bugs.webkit.org/show_bug.cgi?id=118483
+
+        Reviewed by Eric Carlson.
+
+        No new tests since this bug can't be reproduced in layout tests.
+
+        * html/track/WebVTTParser.cpp:
+        (WebCore::WebVTTParser::parseBytes): Only buffer the identifier if we haven't read an entire line.
+
 2013-07-23  Andreas Kling  <akling@apple.com>
 
         REGRESSION(r150867): FrameView auto-sizing + delegate denied image load may cause StyleResolver to re-enter itself.

Source/WebCore/html/track/WebVTTParser.cpp

@@ -151,9 +151,9 @@ void WebVTTParser::parseBytes(const char* data, unsigned length)
 
         switch (m_state) {
         case Initial:
-            // Buffer up at least 9 bytes before proceeding with checking for the file identifier.
+            // Buffer up at least 9 bytes or a full line before proceeding with checking for the file identifier.
             m_identifierData.append(data, length);
-            if (m_identifierData.size() < bomLength + fileIdentifierLength)
+            if (position == line.sizeInBytes() && m_identifierData.size() < bomLength + fileIdentifierLength)
                 return;
 
             // 4-12 - Collect the first line and check for "WEBVTT".