[JENKINS-5073]

Suppressed a confusing 2nd error message.

core/src/main/java/hudson/tasks/CommandInterpreter.java

@@ -31,9 +31,12 @@ import hudson.model.AbstractBuild;
 import hudson.model.BuildListener;
 import hudson.model.Node;
 import hudson.model.TaskListener;
+import hudson.remoting.ChannelClosedException;
 
 import java.io.IOException;
 import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import javax.annotation.Nonnull;
 
 /**
@@ -70,6 +73,7 @@ public abstract class CommandInterpreter extends Builder {
             throw new NullPointerException("no workspace from node " + node + " which is computer " + node.toComputer() + " and has channel " + node.getChannel());
         }
         FilePath script=null;
+        int r = -1;
         try {
             try {
                 script = createScriptFile(ws);
@@ -79,7 +83,6 @@ public abstract class CommandInterpreter extends Builder {
                 return false;
             }
 
-            int r;
             try {
                 EnvVars envVars = build.getEnvironment(listener);
                 // on Windows environment variables are converted to all upper case,
@@ -90,18 +93,28 @@ public abstract class CommandInterpreter extends Builder {
 
                 r = launcher.launch().cmds(buildCommandLine(script)).envs(envVars).stdout(listener).pwd(ws).join();
             } catch (IOException e) {
-                Util.displayIOException(e,listener);
+                Util.displayIOException(e, listener);
                 e.printStackTrace(listener.fatalError(Messages.CommandInterpreter_CommandFailed()));
-                r = -1;
             }
             return r==0;
         } finally {
             try {
                 if(script!=null)
-                script.delete();
+                    script.delete();
             } catch (IOException e) {
-                Util.displayIOException(e,listener);
-                e.printStackTrace( listener.fatalError(Messages.CommandInterpreter_UnableToDelete(script)) );
+                if (r==-1 && e.getCause() instanceof ChannelClosedException) {
+                    // JENKINS-5073
+                    // r==-1 only when the execution of the command resulted in IOException,
+                    // and we've already reported that error. A common error there is channel
+                    // losing a connection, and in that case we don't want to confuse users
+                    // by reporting the 2nd problem. Technically the 1st exception may not be
+                    // a channel closed error, but that's rare enough, and JENKINS-5073 is common enough
+                    // that this suppressing of the error would be justified
+                    LOGGER.log(Level.FINE, "Script deletion failed", e);
+                } else {
+                    Util.displayIOException(e,listener);
+                    e.printStackTrace( listener.fatalError(Messages.CommandInterpreter_UnableToDelete(script)) );
+                }
             } catch (Exception e) {
                 e.printStackTrace( listener.fatalError(Messages.CommandInterpreter_UnableToDelete(script)) );
             }
@@ -120,4 +133,6 @@ public abstract class CommandInterpreter extends Builder {
     protected abstract String getContents();
 
     protected abstract String getFileExtension();
+
+    private static final Logger LOGGER = Logger.getLogger(CommandInterpreter.class.getName());
 }