Index: src/main/org/codehaus/groovy/control/SourceUnit.java
===================================================================
--- src/main/org/codehaus/groovy/control/SourceUnit.java	(revision 22131)
+++ src/main/org/codehaus/groovy/control/SourceUnit.java	(working copy)
@@ -274,6 +274,10 @@
             this.ast.setDescription(this.name);
         }
         catch (SyntaxException e) {
+        	if (this.ast==null) {
+        		// Create a dummy ModuleNode to represent a failed parse - in case a later phase attempts to use the ast
+        		this.ast = new ModuleNode(this);
+        	}
             getErrorCollector().addError(new SyntaxErrorMessage(e, this));
         }