Merge branch 'stable-4.9' into stable-4.10

* stable-4.9:
  ObjectDownloadListener#onWritePossible: Add comment on return statement

Change-Id: I3dff04d2ea99e5b6331e45e3ea2ccc78fb2d5a02
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/fs/ObjectDownloadListener.java

@@ -136,6 +136,10 @@ public class ObjectDownloadListener implements WriteListener {
 					} finally {
 						context.complete();
 					}
+					// This is need to avoid endless loop in recent Jetty versions.
+					// That's because out.isReady() is returning true for already
+					// closed streams and because out.close() doesn't throw any
+					// exception any more when trying to close already closed stream.
 					return;
 				}
 			}