fix for bug 48789 - Pipe broken.

This is an issue that we have been experiencing in the gump runs on Ubuntu.
The tests below will hopefully be fixed by this checkin. 
src/tests/antunit/taskdefs/exec/apply-test.xml : testRedirector13 and testRedirector14 
src/tests/antunit/taskdefs/exec/exec-test.xml  : test-redirector-outputfilterchain-errorfilterchain


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@917817 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -46,7 +46,10 @@ Fixed bugs:
    Bugzilla Report 48816.        
    
 *  <get> with an invalid URL could trigger an NPE in some JVMs.
-   Bugzilla Report 48833 
+   Bugzilla Report 48833
+   
+*  Broken Pipe issue under Ubuntu Linux
+   Bugzilla Report 48789    
 
 Other changes:
 --------------

src/main/org/apache/tools/ant/taskdefs/PumpStreamHandler.java

@@ -129,8 +129,6 @@ public class PumpStreamHandler implements ExecuteStreamHandler {
      * Stop pumping the streams.
      */
     public void stop() {
-        finish(outputThread);
-        finish(errorThread);
 
         if (inputPump != null) {
             inputPump.stop();
@@ -146,6 +144,8 @@ public class PumpStreamHandler implements ExecuteStreamHandler {
         } catch (IOException e) {
             // ignore
         }
+        finish(outputThread);
+        finish(errorThread);
     }
 
     private static final long JOIN_TIMEOUT = 500;