Revert 93704 - Remove Content-Length mismatch checks.

Although the transferred bytes are supposed to match the advertised Content-Length, in practice a small but non-trivial number of sites do not obey this behavior.

BUG=52847
TEST=None


Review URL: http://codereview.chromium.org/7482005

TBR=cbentzel@chromium.org
Review URL: http://codereview.chromium.org/7461040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93710 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 37 insertions, 3 deletions

diff --git a/net/url_request/url_request_http_job.cc b/net/url_request/url_request_http_job.cc
index fbb4a34..4007282 100644
--- a/net/url_request/url_request_http_job.cc
+++ b/net/url_request/url_request_http_job.cc
@@ -751,6 +751,9 @@ void URLRequestHttpJob::OnStartCompleted(int result) {
 void URLRequestHttpJob::OnReadCompleted(int result) {
   read_in_progress_ = false;
 
+  if (ShouldFixMismatchedContentLength(result))
+    result = 0;
+
   if (result == 0) {
     NotifyDone(URLRequestStatus());
   } else if (result < 0) {
@@ -1110,6 +1113,28 @@ void URLRequestHttpJob::ContinueDespiteLastError() {
           &URLRequestHttpJob::OnStartCompleted, rv));
 }
 
+bool URLRequestHttpJob::ShouldFixMismatchedContentLength(int rv) const {
+  // Some servers send the body compressed, but specify the content length as
+  // the uncompressed size.  Although this violates the HTTP spec we want to
+  // support it (as IE and FireFox do), but *only* for an exact match.
+  // See http://crbug.com/79694.
+  if (rv == net::ERR_CONNECTION_CLOSED) {
+    if (request_ && request_->response_headers()) {
+      int64 expected_length = request_->response_headers()->GetContentLength();
+      VLOG(1) << __FUNCTION__ << "() "
+              << "\"" << request_->url().spec() << "\""
+              << " content-length = " << expected_length
+              << " pre total = " << prefilter_bytes_read()
+              << " post total = " << postfilter_bytes_read();
+      if (postfilter_bytes_read() == expected_length) {
+        // Clear the error.
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 bool URLRequestHttpJob::ReadRawData(IOBuffer* buf, int buf_size,
                                     int *bytes_read) {
   DCHECK_NE(buf_size, 0);
@@ -1118,6 +1143,9 @@ bool URLRequestHttpJob::ReadRawData(IOBuffer* buf, int buf_size,
 
   int rv = transaction_->Read(buf, buf_size, &read_callback_);
 
+  if (ShouldFixMismatchedContentLength(rv))
+    rv = 0;
+
   if (rv >= 0) {
     *bytes_read = rv;
     if (!rv)
diff --git a/net/url_request/url_request_http_job.h b/net/url_request/url_request_http_job.h
index 5a6fd6b..c5b045d 100644
--- a/net/url_request/url_request_http_job.h
+++ b/net/url_request/url_request_http_job.h
@@ -161,6 +161,13 @@ class URLRequestHttpJob : public URLRequestJob {
   void RecordPerfHistograms(CompletionCause reason);
   void DoneWithRequest(CompletionCause reason);
 
+  // Some servers send the body compressed, but specify the content length as
+  // the uncompressed size. If this is the case, we return true in order
+  // to request to work around this non-adherence to the HTTP standard.
+  // |rv| is the standard return value of a read function indicating the number
+  // of bytes read or, if negative, an error code.
+  bool ShouldFixMismatchedContentLength(int rv) const;
+
   base::Time request_creation_time_;
 
   // Data used for statistics gathering. This data is only used for histograms
diff --git a/net/url_request/url_request_unittest.cc b/net/url_request/url_request_unittest.cc
index 0378b62..7fe23bf 100644
--- a/net/url_request/url_request_unittest.cc
+++ b/net/url_request/url_request_unittest.cc
@@ -463,11 +463,10 @@ TEST_F(URLRequestTestHTTP, GetZippedTest) {
   const char test_parameters[] = "CULMS";
   const int num_tests = arraysize(test_parameters)- 1;  // Skip NULL.
   // C & U should be OK.
-  // L & M are larger than the data sent, but we still accept it since a number
-  //   of servers in the wild have invalid Content-Lengths.
+  // L & M are larger than the data sent, and show an error.
   // S has too little data, but we seem to accept it.
   const bool test_expect_success[num_tests] =
-      { true, true, true, true, true };
+      { true, true, false, false, true };
 
   for (int i = 0; i < num_tests ; i++) {
     TestDelegate d;