Embedding-CSP: Fixing path matching

third_party/WebKit/Source/core/frame/csp/CSPSource.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/csp/CSPSource.h"
 
 #include "core/frame/UseCounter.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "platform/weborigin/KURL.h"
 #include "platform/weborigin/KnownPorts.h"
@@ skipping 56 matching lines @@
       UseCounter::count(*document,
                         UseCounter::CSPSourceWildcardWouldMatchExactHost);
   } else {
     match = equalHosts;
   }
 
   return match;
 }
 
 bool CSPSource::pathMatches(const String& urlPath) const {
-  if (m_path.isEmpty())
+  if (m_path.isEmpty() || (m_path == "/" && urlPath.isEmpty()))
     return true;
 
   String path = decodeURLEscapeSequences(urlPath);
 
   if (m_path.endsWith("/"))
     return path.startsWith(m_path);
 
   return path == m_path;
 }
 
@@ skipping 59 matching lines @@
 
   String scheme = other->schemeMatches(m_scheme) ? m_scheme : other->m_scheme;
   if (isSchemeOnly() || other->isSchemeOnly()) {
     const CSPSource* stricter = isSchemeOnly() ? other : this;
     return new CSPSource(m_policy, scheme, stricter->m_host, stricter->m_port,
                          stricter->m_path, stricter->m_hostWildcard,
                          stricter->m_portWildcard);
   }
 
   String host = m_hostWildcard == NoWildcard ? m_host : other->m_host;
-  String path = other->pathMatches(m_path) ? m_path : other->m_path;
+  // Since sources are similar and paths match, pick the longer one.
+  String path =
+      m_path.length() > other->m_path.length() ? m_path : other->m_path;

[amalika, 2016/12/08 19:30:59]

Simplified the logic instead of adding another check. 

   // Choose this port if the other port is empty, has wildcard or is a port for
   // a less secure scheme such as "http" whereas scheme of this is "https", in
   // which case the lengths would differ.
   int port = (other->m_portWildcard == HasWildcard || !other->m_port ||
               m_scheme.length() > other->m_scheme.length())
                  ? m_port
                  : other->m_port;
   WildcardDisposition hostWildcard =
       (m_hostWildcard == HasWildcard) ? other->m_hostWildcard : m_hostWildcard;
   WildcardDisposition portWildcard =
@@ skipping 26 matching lines @@
       return false;
   }
   return true;
 }
 
 DEFINE_TRACE(CSPSource) {
   visitor->trace(m_policy);
 }
 
 }  // namespace blink