guard for NPE.

diff --git a/asm/src/org/aspectj/asm/internal/ProgramElement.java b/asm/src/org/aspectj/asm/internal/ProgramElement.java
index 913a1cebceebd5a30fc81a6df0f97f7064e2eb6a..ef4b285070689829b8b484ffad4db96d9af73bad 100644 (file)
--- a/asm/src/org/aspectj/asm/internal/ProgramElement.java
+++ b/asm/src/org/aspectj/asm/internal/ProgramElement.java
@@ -353,10 +353,12 @@ public class ProgramElement implements IProgramElement {
 //     }
 
        public IProgramElement walk(HierarchyWalker walker) {
+               if (children!=null) {
                for (Iterator it = children.iterator(); it.hasNext(); ) {
                        IProgramElement child = (IProgramElement)it.next();
                        walker.process(child);  
                } 
+               }
                return this;
        }