1 files changed, 58 insertions, 2 deletions

diff --git a/net/url_request/url_request_http_job.cc b/net/url_request/url_request_http_job.cc
index fe1332d..4539f13 100644
--- a/net/url_request/url_request_http_job.cc
+++ b/net/url_request/url_request_http_job.cc
@@ -173,11 +173,65 @@ bool URLRequestHttpJob::GetContentEncodings(
   void* iter = NULL;
   while (response_info_->headers->EnumerateHeader(&iter, "Content-Encoding",
                                                   &encoding_type)) {
-    encoding_types->push_back(encoding_type);
+    encoding_types->push_back(StringToLowerASCII(encoding_type));
   }
+
+  // TODO(jar): Transition to returning enums, rather than strings, and perform
+  // all content encoding fixups here, rather than doing some in the
+  // FilterFactor().  Note that enums generated can be more specific than mere
+  // restatement of strings.  For example, rather than just having a GZIP
+  // encoding we can have a GZIP_OPTIONAL encoding to help with odd SDCH related
+  // fixups.
+
+  // TODO(jar): Refactor code so that content-encoding error recovery is
+  // testable via unit tests.
+
+  if (!IsSdchResponse())
+    return !encoding_types->empty();
+
+  // If content encoding included SDCH, then everything is fine.
+  if (!encoding_types->empty() && ("sdch" == encoding_types->front()))
+    return !encoding_types->empty();
+
+  // SDCH "search results" protective hack: To make sure we don't break the only
+  // currently deployed SDCH enabled server, be VERY cautious about proxies that
+  // strip all content-encoding to not include sdch.  IF we don't see content
+  // encodings that seem to match what we'd expect from a server that asked us
+  // to use a dictionary (and we advertised said dictionary in the GET), then
+  // we set the encoding to (try to) use SDCH to decode.  Note that SDCH will
+  // degrade into a pass-through filter if it doesn't have a viable dictionary
+  // hash in its header.  Also note that a solo "sdch" will implicitly create
+  // a "sdch,gzip" decoding filter, where the gzip portion will degrade to a
+  // pass through if a gzip header is not encountered.  Hence we can replace
+  // "gzip" with "sdch" and "everything will work."
+  // The one failure mode comes when we advertise a dictionary, and the server
+  // tries to *send* a gzipped file (not gzip encode content), and then we could
+  // do a gzip decode :-(.  Since current server support does not ever see such
+  // a transfer, we are safe (for now).
+
+  std::string mime_type;
+  GetMimeType(&mime_type);
+  if (std::string::npos != mime_type.find_first_of("text/html")) {
+    // Suspicious case: Advertised dictionary, but server didn't use sdch, even
+    // though it is text_html content.
+    if (encoding_types->empty())
+      SdchManager::SdchErrorRecovery(SdchManager::ADDED_CONTENT_ENCODING);
+    else if (encoding_types->size() == 1)
+      SdchManager::SdchErrorRecovery(SdchManager::FIXED_CONTENT_ENCODING);
+    else
+      SdchManager::SdchErrorRecovery(SdchManager::FIXED_CONTENT_ENCODINGS);
+    encoding_types->clear();
+    encoding_types->push_back("sdch");  // Handle SDCH/GZIP-opt encoding.
+  }
+
   return !encoding_types->empty();
 }
 
+bool URLRequestHttpJob::IsSdchResponse() const {
+  return response_info_ &&
+      (request_info_.load_flags & net::LOAD_SDCH_DICTIONARY_ADVERTISED);
+}
+
 bool URLRequestHttpJob::IsRedirectResponse(GURL* location,
                                            int* http_status_code) {
   if (!response_info_)
@@ -516,9 +570,11 @@ void URLRequestHttpJob::AddExtraHeaders() {
   std::string avail_dictionaries;
   SdchManager::Global()->GetAvailDictionaryList(request_->url(),
                                                 &avail_dictionaries);
-  if (!avail_dictionaries.empty())
+  if (!avail_dictionaries.empty()) {
     request_info_.extra_headers += "Avail-Dictionary: "
         + avail_dictionaries + "\r\n";
+    request_info_.load_flags |= net::LOAD_SDCH_DICTIONARY_ADVERTISED;
+  }
 
   scoped_ptr<FileVersionInfo> file_version_info(
     FileVersionInfo::CreateFileVersionInfoForCurrentModule());