Issue #6642 - use request UPGRADE_CONNECTION_ATTRIBUTE instead of 101…

… response.

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-server/src/main/java/org/eclipse/jetty/server/HttpConnection.java

@@ -28,7 +28,6 @@
 import org.eclipse.jetty.http.HttpHeaderValue;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpParser;
-import org.eclipse.jetty.http.HttpStatus;
 import org.eclipse.jetty.http.MetaData;
 import org.eclipse.jetty.http.PreEncodedHttpField;
 import org.eclipse.jetty.io.AbstractConnection;
@@ -886,7 +885,7 @@ private void releaseChunk()
         @Override
         protected void onCompleteSuccess()
         {
-            boolean upgrading = _info != null && _info.getStatus() == HttpStatus.SWITCHING_PROTOCOLS_101;
+            boolean upgrading = _channel.getRequest().getAttribute(UPGRADE_CONNECTION_ATTRIBUTE) != null;
             release().succeeded();
             // If successfully upgraded it is responsibility of the next protocol to close the connection.
             if (_shutdownOut && !upgrading)