only add classpath elements to existing loaders, not to a freshly created one. PR 45847.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@698943 13f79535-47bb-0310-9956-ffa450edef68

CONTRIBUTORS

@@ -236,6 +236,7 @@ Ray Waldin
 Richard Evans
 Rick Beton
 Robert Anderson
+Robert Flaherty
 Robert Shaw
 Robert Watkins
 Roberto Scaramuzzi

contributors.xml

@@ -960,6 +960,10 @@
     <first>Robert</first>
     <last>Anderson</last>
   </name>
+  <name>
+    <first>Robert</first>
+    <last>Flaherty</last>
+  </name>
   <name>
     <first>Robert</first>
     <last>Shaw</last>

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

@@ -185,6 +185,7 @@ public class Classloader extends Task {
             }
 
             AntClassLoader acl = (AntClassLoader) obj;
+            boolean existingLoader = acl != null;
 
             if (acl == null) {
                 // Construct a new class loader
@@ -220,7 +221,8 @@ public class Classloader extends Task {
                     getProject().setCoreLoader(acl);
                 }
             }
-            if (classpath != null) {
+
+            if (existingLoader && classpath != null) {
                 String[] list = classpath.list();
                 for (int i = 0; i < list.length; i++) {
                     File f = new File(list[i]);