[FIXED JENKINS-12037] CLI - I/O error in channel Chunked connection

Use a ping timeout of 3/4 of the ping interval instead of the default
4 minute timeout.
This happens to workaround an issue in the remoting PingThread
implementation which causes the ping to busy wait for the timeout
period instead of keeping the channel alive.

changelog.html

@@ -55,6 +55,9 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
+  <li class=bug>
+    CLI - I/O error in channel Chunked connection/Unexpected termination of the channel - still occuring in Jenkins 1.449.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-12037">issue 12037</a>)
   <li class=bug>
     Quiet period is blocking other jobs in queue.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-12994">issue 12994</a>)  

cli/src/main/java/hudson/cli/CLI.java

@@ -150,7 +150,9 @@ public class CLI {
         FullDuplexHttpStream con = new FullDuplexHttpStream(jenkins,authorization);
         Channel ch = new Channel("Chunked connection to "+jenkins,
                 pool,con.getInputStream(),con.getOutputStream());
-        new PingThread(ch,15*1000) {
+        final long interval = 15*1000;
+        final long timeout = (interval * 3) / 4;
+        new PingThread(ch,timeout,interval) {
             protected void onDead() {
                 // noop. the point of ping is to keep the connection alive
                 // as most HTTP servers have a rather short read time out