property environment=.. failed under JDK 1.2 with a NPE because WinNTCommandLauncher.exec() got a null working directory and a null Project - reported by <Aimee.Ukasick@med.ge.com>

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269505 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -627,8 +627,12 @@ public class Execute {
         public Process exec(Project project, String[] cmd, String[] env, File workingDir) throws IOException
         {
             File commandDir = workingDir;
-            if ( workingDir == null && project != null ) {
-                commandDir = project.getBaseDir();
+            if ( workingDir == null ) {
+                if ( project != null ) {
+                    commandDir = project.getBaseDir();
+                } else {
+                    return exec(project, cmd, env);
+                }
             }
 
             // Use cmd.exe to change to the specified directory before running