Fix a compiler assertion

javatools/src/main/java/org/xvm/compiler/ast/NewExpression.java

@@ -823,6 +823,17 @@ else if (fNestMate && typeTarget.isVirtualChild() || typeTarget.isInnerChildClas
             m_mapRegisters   = ctxAnon.ensureRegisterMap();
             m_fInstanceChild = ctxAnon.isInstanceChild();
             m_ctxCapture     = null;
+
+            // make sure the capture names don't collide
+            ClassStructure clzAnon = ctxAnon.getThisClass();
+            for (String sName : m_mapCapture.keySet())
+                {
+                if (clzAnon.getChild(sName) != null)
+                    {
+                    log(errs, Severity.ERROR, Compiler.NAME_COLLISION, sName);
+                    return null;
+                    }
+                }
             }
 
         m_plan = plan;

manualTests/src/main/x/TestSimple.x

@@ -1,40 +1,24 @@
-    module TestSimple {
-        @Inject Console console;
+module TestSimple {
+    @Inject Console console;
 
-        void run() {
-            Callback[] callbacks = new Array();
-            callbacks.add(new MyCallbackOne());
-            callbacks.add(new MyCallbackTwo());
+    void run() {
+    }
 
-            // the line below used to throw TypeMismatch at run-time; it no longer compiles
-            // Callback[] filtered = callbacks.filter(c -> !c.is(MyCallbackOne));
-            Collection<Callback> filtered = callbacks.filter(c -> !c.is(MyCallbackOne));
-            for (Callback callback : filtered) {
-                callback.call();
-            }
-
-            for (Callback callback : callbacks.filter(c -> c.is(MyCallbackOne))) {
-                callback.call();
-            }
-        }
-
-        interface Callback {
-            void call();
-        }
-
-        const MyCallbackOne
-                implements Callback {
-            @Override
-            void call() {
-                console.print("one");
-            }
-        }
+    Iterator<Int> test(Int next) { // the name collision used to assert the compiler
+        return new Iterator<Int>() {
+            private Int nextValue = next;
+            private Boolean hasNext = True;
 
-        const MyCallbackTwo
-                implements Callback {
             @Override
-            void call() {
-                console.print("two");
+            conditional Element next() {
+                if (hasNext) {
+                    Int value = nextValue;
+                    hasNext = False;
+                    return True, value;
+                } else {
+                    return False;
+                }
             }
-        }
-    }
+        };
+    }
+}