net/http: don't special-case multipart/byteranges responses

Fixes #4767

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/7435046

src/pkg/net/http/response_test.go

@@ -324,6 +324,30 @@ var respTests = []respTest{
 
 		"",
 	},
+
+	// golang.org/issue/4767: don't special-case multipart/byteranges responses
+	{
+		`HTTP/1.1 206 Partial Content
+Connection: close
+Content-Type: multipart/byteranges; boundary=18a75608c8f47cef
+
+some body`,
+		Response{
+			Status:     "206 Partial Content",
+			StatusCode: 206,
+			Proto:      "HTTP/1.1",
+			ProtoMajor: 1,
+			ProtoMinor: 1,
+			Request:    dummyReq("GET"),
+			Header: Header{
+				"Content-Type": []string{"multipart/byteranges; boundary=18a75608c8f47cef"},
+			},
+			Close:         true,
+			ContentLength: -1,
+		},
+
+		"some body",
+	},
 }
 
 func TestReadResponse(t *testing.T) {

src/pkg/net/http/transfer.go

@@ -454,13 +454,6 @@ func fixLength(isResponse bool, status int, requestMethod string, header Header,
 		return 0, nil
 	}
 
-	// Logic based on media type. The purpose of the following code is just
-	// to detect whether the unsupported "multipart/byteranges" is being
-	// used. A proper Content-Type parser is needed in the future.
-	if strings.Contains(strings.ToLower(header.get("Content-Type")), "multipart/byteranges") {
-		return -1, ErrNotSupported
-	}
-
 	// Body-EOF logic based on other methods (like closing, or chunked coding)
 	return -1, nil
 }