IDEA-123484 anonymous from traits are not allowed

plugins/groovy/src/org/jetbrains/plugins/groovy/GroovyBundle.properties

@@ -376,3 +376,4 @@ declared.type.0.have.to.extend.script=Declared type ''{0}'' does not extend 'gro
 base.script.annotation.is.allowed.only.inside.scripts=Annotation @BaseScript can only be used within a script
 0.expressions.on.trait.fields.properties.are.not.supported.in.traits={0} expressions on trait fields/properties are not supported in traits
 only.traits.expected.here=Only traits are expected here
+anonymous.classes.cannot.be.created.from.traits=Anonymous classes cannot be created from traits

plugins/groovy/src/org/jetbrains/plugins/groovy/annotator/GroovyAnnotator.java

@@ -2001,9 +2001,13 @@ public class GroovyAnnotator extends GroovyElementVisitor {
     final GroovyConfigUtils configUtils = GroovyConfigUtils.getInstance();
     if (typeDefinition.isAnonymous()) {
       if (!configUtils.isVersionAtLeast(typeDefinition, GroovyConfigUtils.GROOVY1_7)) {
-        holder.createErrorAnnotation(typeDefinition.getNameIdentifierGroovy(), GroovyBundle.message("anonymous.classes.are.not.supported",
-                                                                                                    configUtils
-                                                                                                      .getSDKVersion(typeDefinition)));
+        holder.createErrorAnnotation(typeDefinition.getNameIdentifierGroovy(),
+                                     GroovyBundle.message("anonymous.classes.are.not.supported", configUtils.getSDKVersion(typeDefinition)));
+      }
+
+      PsiElement superClass = ((PsiAnonymousClass)typeDefinition).getBaseClassReference().resolve();
+      if (superClass instanceof GrTypeDefinition && ((GrTypeDefinition)superClass).isTrait()) {
+        holder.createErrorAnnotation(typeDefinition.getNameIdentifierGroovy(), GroovyBundle.message("anonymous.classes.cannot.be.created.from.traits"));
       }
     }
     else if (typeDefinition.getContainingClass() != null && !(typeDefinition instanceof GrEnumTypeDefinition)) {

plugins/groovy/test/org/jetbrains/plugins/groovy/lang/highlighting/GroovyHighlightingTest.groovy

@@ -1868,6 +1868,14 @@ trait C {
     <error descr="++ expressions on trait fields/properties are not supported in traits">x++</error>
   }
 }
+''')
+  }
+
+  void testTraitAsAnonymous() {
+    testHighlighting('''
+trait T {}
+
+new <error descr="Anonymous classes cannot be created from traits">T</error>(){}
 ''')
   }
 }