Fix Accepted-Encoding to "identity" whenever there's a range request

Unit test for encoding advertisement on range requests.


Simple logic to change accepted encoding to identity in a range request

Bug: 849952
Change-Id: I436ac5e4db118faa4f362a0b8c1943b5fe7020ea
Reviewed-on: https://chromium-review.googlesource.com/c/1352672Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Aaron Tagliaboschi <aarontag@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612816}

net/url_request/url_request_http_job.cc

@@ -645,6 +645,12 @@ void URLRequestHttpJob::StartTransactionInternal() {
 void URLRequestHttpJob::AddExtraHeaders() {
   if (!request_info_.extra_headers.HasHeader(
           HttpRequestHeaders::kAcceptEncoding)) {
+    // If a range is specifically requested, set the "Accepted Encoding" header
+    // to "identity"
+    if (request_info_.extra_headers.HasHeader(HttpRequestHeaders::kRange)) {
+      request_info_.extra_headers.SetHeader(HttpRequestHeaders::kAcceptEncoding,
+                                            "identity");
+    } else {
       // Advertise "br" encoding only if transferred data is opaque to proxy.
       bool advertise_brotli = false;
       if (request()->context()->enable_brotli()) {
@@ -654,11 +660,11 @@ void URLRequestHttpJob::AddExtraHeaders() {
         }
       }
 
-    // Supply Accept-Encoding headers first so that it is more likely that they
-    // will be in the first transmitted packet. This can sometimes make it
-    // easier to filter and analyze the streams to assure that a proxy has not
-    // damaged these headers. Some proxies deliberately corrupt Accept-Encoding
-    // headers.
+      // Supply Accept-Encoding headers first so that it is more likely that
+      // they will be in the first transmitted packet. This can sometimes make
+      // it easier to filter and analyze the streams to assure that a proxy has
+      // not damaged these headers. Some proxies deliberately corrupt
+      // Accept-Encoding headers.
       std::string advertised_encodings = "gzip, deflate";
       if (advertise_brotli)
         advertised_encodings += ", br";
@@ -666,6 +672,7 @@ void URLRequestHttpJob::AddExtraHeaders() {
       request_info_.extra_headers.SetHeader(HttpRequestHeaders::kAcceptEncoding,
                                             advertised_encodings);
     }
+  }
 
   if (http_user_agent_settings_) {
     // Only add default Accept-Language if the request didn't have it

net/url_request/url_request_http_job_unittest.cc

@@ -1209,6 +1209,82 @@ TEST_F(URLRequestHttpJobWithMockSocketsTest,
   histograms.ExpectTotalCount(kCTRequiredHistogramName, 0);
 }
 
+TEST_F(URLRequestHttpJobWithMockSocketsTest, EncodingAdvertisementOnRange) {
+  MockWrite writes[] = {
+      MockWrite("GET / HTTP/1.1\r\n"
+                "Host: www.example.com\r\n"
+                "Connection: keep-alive\r\n"
+                "User-Agent: \r\n"
+                "Accept-Encoding: identity\r\n"
+                "Accept-Language: en-us,fr\r\n"
+                "Range: bytes=0-1023\r\n\r\n")};
+
+  MockRead reads[] = {MockRead("HTTP/1.1 200 OK\r\n"
+                               "Accept-Ranges: bytes\r\n"
+                               "Content-Length: 12\r\n\r\n"),
+                      MockRead("Test Content")};
+
+  StaticSocketDataProvider socket_data(reads, writes);
+  socket_factory_.AddSocketDataProvider(&socket_data);
+
+  TestDelegate delegate;
+  std::unique_ptr<URLRequest> request =
+      context_->CreateRequest(GURL("http://www.example.com"), DEFAULT_PRIORITY,
+                              &delegate, TRAFFIC_ANNOTATION_FOR_TESTS);
+
+  // Make the extra header to trigger the change in "Accepted-Encoding"
+  HttpRequestHeaders headers;
+  headers.SetHeader("Range", "bytes=0-1023");
+  request->SetExtraRequestHeaders(headers);
+
+  request->Start();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_THAT(delegate.request_status(), IsOk());
+  EXPECT_EQ(12, request->received_response_content_length());
+  EXPECT_EQ(CountWriteBytes(writes), request->GetTotalSentBytes());
+  EXPECT_EQ(CountReadBytes(reads), request->GetTotalReceivedBytes());
+}
+
+TEST_F(URLRequestHttpJobWithMockSocketsTest, RangeRequestOverrideEncoding) {
+  MockWrite writes[] = {
+      MockWrite("GET / HTTP/1.1\r\n"
+                "Host: www.example.com\r\n"
+                "Connection: keep-alive\r\n"
+                "Accept-Encoding: gzip, deflate\r\n"
+                "User-Agent: \r\n"
+                "Accept-Language: en-us,fr\r\n"
+                "Range: bytes=0-1023\r\n\r\n")};
+
+  MockRead reads[] = {MockRead("HTTP/1.1 200 OK\r\n"
+                               "Accept-Ranges: bytes\r\n"
+                               "Content-Length: 12\r\n\r\n"),
+                      MockRead("Test Content")};
+
+  StaticSocketDataProvider socket_data(reads, writes);
+  socket_factory_.AddSocketDataProvider(&socket_data);
+
+  TestDelegate delegate;
+  std::unique_ptr<URLRequest> request =
+      context_->CreateRequest(GURL("http://www.example.com"), DEFAULT_PRIORITY,
+                              &delegate, TRAFFIC_ANNOTATION_FOR_TESTS);
+
+  // Explicitly set "Accept-Encoding" to make sure it's not overridden by
+  // AddExtraHeaders
+  HttpRequestHeaders headers;
+  headers.SetHeader("Accept-Encoding", "gzip, deflate");
+  headers.SetHeader("Range", "bytes=0-1023");
+  request->SetExtraRequestHeaders(headers);
+
+  request->Start();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_THAT(delegate.request_status(), IsOk());
+  EXPECT_EQ(12, request->received_response_content_length());
+  EXPECT_EQ(CountWriteBytes(writes), request->GetTotalSentBytes());
+  EXPECT_EQ(CountReadBytes(reads), request->GetTotalReceivedBytes());
+}
+
 TEST_F(URLRequestHttpJobTest, TestCancelWhileReadingCookies) {
   DelayedCookieMonster cookie_monster;
   TestURLRequestContext context(true);

third_party/blink/web_tests/external/wpt/fetch/range/general.any-expected.txt

-This is a testharness.js-based test.
-PASS Range header setting allowed for guard type: none
-PASS Range header setting allowed for guard type: response
-PASS Range header setting allowed for guard type: request
-PASS Privileged header not allowed for guard type: request-no-cors
-FAIL Fetch with range header will be sent with Accept-Encoding: identity assert_equals: Expect identity accept-encoding if range header is "bytes=0-10" expected "identity" but got "gzip, deflate"
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/fetch/range/general.any.worker-expected.txt

-This is a testharness.js-based test.
-PASS Range header setting allowed for guard type: none
-PASS Range header setting allowed for guard type: response
-PASS Range header setting allowed for guard type: request
-PASS Privileged header not allowed for guard type: request-no-cors
-FAIL Fetch with range header will be sent with Accept-Encoding: identity assert_equals: Expect identity accept-encoding if range header is "bytes=0-10" expected "identity" but got "gzip, deflate"
-Harness: the test ran to completion.
-