GROOVY-6072: "String | []" is converted to a ClassExpression at seman…

…tic analysis

src/main/org/codehaus/groovy/control/ResolveVisitor.java

@@ -872,6 +872,13 @@ private boolean testVanillaNameForClass(String name) {
         return !Character.isLowerCase(name.charAt(0));
     }
 
+    private boolean isLeftSquareBracket(int op) {
+        return op == Types.ARRAY_EXPRESSION
+                || op == Types.LEFT_SQUARE_BRACKET
+                || op == Types.SYNTH_LIST
+                || op == Types.SYNTH_MAP;
+    }
+
     protected Expression transformBinaryExpression(BinaryExpression be) {
         Expression left = transform(be.getLeftExpression());
         int type = be.getOperation().getType();
@@ -885,7 +892,7 @@ protected Expression transformBinaryExpression(BinaryExpression be) {
             addError(error, be.getLeftExpression());
             return be;
         }
-        if (left instanceof ClassExpression) {
+        if (left instanceof ClassExpression && isLeftSquareBracket(type)) {
             if (be.getRightExpression() instanceof ListExpression) {
                 ListExpression list = (ListExpression) be.getRightExpression();
                 if (list.getExpressions().isEmpty()) {

src/test/groovy/bugs/Groovy6072Bug.groovy

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2003-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package groovy.bugs
+
+class Groovy6072Bug extends GroovyTestCase {
+    void testShouldNotChangeBinExpToClassExp() {
+        assertScript '''import groovy.transform.ASTTest
+            import org.codehaus.groovy.ast.expr.BinaryExpression
+
+            class OhNo {}
+
+            try {
+            @ASTTest(phase=CANONICALIZATION, value={
+                def right = node.rightExpression
+                assert right instanceof BinaryExpression
+            })
+            def expr1 = OhNo | []
+
+            @ASTTest(phase=SEMANTIC_ANALYSIS, value={
+                def right = node.rightExpression
+                assert right instanceof BinaryExpression
+            })
+            def expr2 = OhNo | []
+            } catch (MissingMethodException ex) {
+                assert ex.message.contains('or()')
+                // alright, what we wanted to test has gone
+            }
+        '''
+    }
+}