Don't use SVG resource documents with an unrecognized MIME-type

third_party/WebKit/Source/core/fetch/Resource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 17 matching lines @@
 #include "core/fetch/FetchInitiatorTypeNames.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceClient.h"
 #include "core/fetch/ResourceClientWalker.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/fetch/ResourceLoader.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "platform/Logging.h"
 #include "platform/SharedBuffer.h"
 #include "platform/TraceEvent.h"
+#include "platform/network/HTTPParsers.h"
 #include "platform/weborigin/KURL.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebProcessMemoryDump.h"
 #include "public/platform/WebScheduler.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/MathExtras.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/Vector.h"
 #include "wtf/WeakPtr.h"
 #include "wtf/text/CString.h"
@@ skipping 263 matching lines @@
 void Resource::finish()
 {
     ASSERT(m_revalidatingRequest.isNull());
     ASSERT(!errorOccurred());
     finishOnePart();
     markClientsFinished();
     if (!errorOccurred())
         m_status = Cached;
 }
 
+AtomicString Resource::httpContentType() const
+{
+    return extractMIMETypeFromMediaType(m_response.httpHeaderField(HTTPNames::Content_Type)).lower();

[Mike West, 2016/02/24 13:23:44]

Would you mind adding some unit tests for this method (maybe in
`HTTPParserTest.cpp`)? It doesn't look like we're actually testing the result of
extractMIMETypeFromMediaType anywhere (sorry!).

Also, we should probably call `lower()` on the header value rather than the
result of the extraction so that we don't construct more AtomicStrings than we
need to. I also wonder whether the extraction function should be taking care of
lowering for us.

[fs, 2016/02/24 17:04:59]

Not sure if there was anything in particular you wanted me to test, so I just
did a "monkey read code, monkey write unit-test" routine.
Done. (Since it's "AtomicString in, AtomicString out" I'm not sure it makes much
of a difference though?)
I guess it could make sense - looking at the current users the majority either
does .lower() (before or after) or use equalIgnoringCase. I only see one of the
uses that doesn't (NetworkResourcesData::responseReceived), but it probably
wouldn't hurt there either. I can do that as a follow-up if you like.

+}
+
 bool Resource::passesAccessControlCheck(SecurityOrigin* securityOrigin) const
 {
     String ignoredErrorDescription;
     return passesAccessControlCheck(securityOrigin, ignoredErrorDescription);
 }
 
 bool Resource::passesAccessControlCheck(SecurityOrigin* securityOrigin, String& errorDescription) const
 {
     return blink::passesAccessControlCheck(m_response, lastResourceRequest().allowStoredCredentials() ? AllowStoredCredentials : DoNotAllowStoredCredentials, securityOrigin, errorDescription, lastResourceRequest().requestContext());
 }
@@ skipping 780 matching lines @@
     case Resource::Media:
         return "Media";
     case Resource::Manifest:
         return "Manifest";
     }
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 
 } // namespace blink