Fix for #6288

NullPointerException if no environment variables found

Patch supplied by jimbuuck@netscape.net


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271191 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -209,7 +209,9 @@ public class Execute {
                 }
             }
             // Since we "look ahead" before adding, there's one last env var.
-            procEnvironment.addElement(var);
+            if (var != null) {
+                procEnvironment.addElement(var);
+            }
         }
         catch (java.io.IOException exc) {
             exc.printStackTrace();