3 files changed, 70 insertions, 2 deletions
diff --git a/src/net/http/response_test.go b/src/net/http/response_test.go
index 2dd0fad11..06e940d9a 100644
--- a/src/net/http/response_test.go
+++ b/src/net/http/response_test.go
@@ -377,6 +377,34 @@ some body`,
 
 		"Body here\n",
 	},
+
+	// 206 Partial Content. golang.org/issue/8923
+	{
+		"HTTP/1.1 206 Partial Content\r\n" +
+			"Content-Type: text/plain; charset=utf-8\r\n" +
+			"Accept-Ranges: bytes\r\n" +
+			"Content-Range: bytes 0-5/1862\r\n" +
+			"Content-Length: 6\r\n\r\n" +
+			"foobar",
+
+		Response{
+			Status:     "206 Partial Content",
+			StatusCode: 206,
+			Proto:      "HTTP/1.1",
+			ProtoMajor: 1,
+			ProtoMinor: 1,
+			Request:    dummyReq("GET"),
+			Header: Header{
+				"Accept-Ranges":  []string{"bytes"},
+				"Content-Length": []string{"6"},
+				"Content-Type":   []string{"text/plain; charset=utf-8"},
+				"Content-Range":  []string{"bytes 0-5/1862"},
+			},
+			ContentLength: 6,
+		},
+
+		"foobar",
+	},
 }
 
 func TestReadResponse(t *testing.T) {
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 70e574fc8..782f7cd39 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -1040,11 +1040,14 @@ func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err err
 	}
 
 	// Ask for a compressed version if the caller didn't set their
-	// own value for Accept-Encoding. We only attempted to
+	// own value for Accept-Encoding. We only attempt to
 	// uncompress the gzip stream if we were the layer that
 	// requested it.
 	requestedGzip := false
-	if !pc.t.DisableCompression && req.Header.Get("Accept-Encoding") == "" && req.Method != "HEAD" {
+	if !pc.t.DisableCompression &&
+		req.Header.Get("Accept-Encoding") == "" &&
+		req.Header.Get("Range") == "" &&
+		req.Method != "HEAD" {
 		// Request gzip only, not deflate. Deflate is ambiguous and
 		// not as universally supported anyway.
 		// See: http://www.gzip.org/zlib/zlib_faq.html#faq38
@@ -1053,6 +1056,10 @@ func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err err
 		// due to a bug in nginx:
 		//   http://trac.nginx.org/nginx/ticket/358
 		//   http://golang.org/issue/5522
+		//
+		// We don't request gzip if the request is for a range, since
+		// auto-decoding a portion of a gzipped document will just fail
+		// anyway. See http://golang.org/issue/8923
 		requestedGzip = true
 		req.extraHeaders().Set("Accept-Encoding", "gzip")
 	}
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index 66fcc3c7d..defa63370 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -2216,6 +2216,39 @@ func TestTransportCloseIdleConnsThenReturn(t *testing.T) {
 	wantIdle("after final put", 1)
 }
 
+// This tests that an client requesting a content range won't also
+// implicitly ask for gzip support. If they want that, they need to do it
+// on their own.
+// golang.org/issue/8923
+func TestTransportRangeAndGzip(t *testing.T) {
+	defer afterTest(t)
+	reqc := make(chan *Request, 1)
+	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
+		reqc <- r
+	}))
+	defer ts.Close()
+
+	req, _ := NewRequest("GET", ts.URL, nil)
+	req.Header.Set("Range", "bytes=7-11")
+	res, err := DefaultClient.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	select {
+	case r := <-reqc:
+		if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
+			t.Error("Transport advertised gzip support in the Accept header")
+		}
+		if r.Header.Get("Range") == "" {
+			t.Error("no Range in request")
+		}
+	case <-time.After(10 * time.Second):
+		t.Fatal("timeout")
+	}
+	res.Body.Close()
+}
+
 func wantBody(res *http.Response, err error, want string) error {
 	if err != nil {
 		return err