From 9b29322cc46d2345c447ceca17d1f2dd6a54840d Mon Sep 17 00:00:00 2001
From: "Jesse N. Glick" <jglick@apache.org>
Date: Tue, 8 Aug 2006 23:43:07 +0000
Subject: [PATCH] Avoid a useless exception being (sometimes) thrown if a <java
 fork="true"> task is halted with Thread.stop().

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@429887 13f79535-47bb-0310-9956-ffa450edef68
---
 src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java b/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java
index 24faf683b..aae0eea28 100644
--- a/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java
+++ b/src/main/org/apache/tools/ant/taskdefs/ProcessDestroyer.java
@@ -142,7 +142,10 @@ class ProcessDestroyer implements Runnable {
             // eligible for garbage collection
             // Cf.: http://developer.java.sun.com/developer/bugParade/bugs/4533087.html
             destroyProcessThread.setShouldDestroy(false);
-            destroyProcessThread.start();
+            if (!destroyProcessThread.getThreadGroup().isDestroyed()) {
+                // start() would throw IllegalThreadStateException from ThreadGroup.add if it were destroyed
+                destroyProcessThread.start();
+            }
             // this should return quickly, since it basically is a NO-OP.
             try {
                 destroyProcessThread.join(20000);