[Regression fix] [Data URI parser] Accept data URI with invalid mediatype data

net/base/data_url.cc

Index: net/base/data_url.cc
diff --git a/net/base/data_url.cc b/net/base/data_url.cc
index 0ec345ea6dbf4f89ed5701e132109e6c7e411a41..2146755e8f056a8ff5b159abec08216a1473e996 100644
--- a/net/base/data_url.cc
+++ b/net/base/data_url.cc
@@ -68,8 +68,6 @@ bool DataURL::Parse(const GURL& url, std::string* mime_type,
   if (mime_type->empty()) {
     // fallback to defaults if nothing specified in the URL:
     mime_type->assign("text/plain");
-  } else if (!ParseMimeTypeWithoutParameter(*mime_type, NULL, NULL)) {

[asanka, 2014/09/24 00:11:38]

As mentioned elsewhere, it's still a bit worrisome that the mime_type is going
to be returned without any validation which places a heavy burden on callers to
do the validation themselves. E.g. someone stuffing the mime type into a set of
headers might inadvertently be open to a header splitting attack. This is partly
why I suggested that we at least treat invalid mediatypes the same as we treat
empty mediatypes.

[tyoshino (SeeGerritForStatus), 2014/09/24 05:43:29]

Good point. It's been a while since I added this check. So, there could be some
new code that depends on this check.

OK. I'll make it fall back to the default ("text/plain") when the media type is
invalid instead of returning false.

-    return false;
   }
   if (charset->empty())
     charset->assign("US-ASCII");