Debug highlighting for error types

compiler/frontend/src/org/jetbrains/jet/lang/types/ErrorUtils.java

@@ -1,6 +1,7 @@
 package org.jetbrains.jet.lang.types;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
@@ -196,10 +197,22 @@ public class ErrorUtils {
     }
 
     public static boolean isErrorType(@NotNull JetType type) {
-        return type != TypeUtils.NO_EXPECTED_TYPE &&(
+        return type != TypeUtils.NO_EXPECTED_TYPE && !(type instanceof NamespaceType) &&
-               (type instanceof DeferredType && ((DeferredType) type).getActualType() == null) ||
+               (
-               type instanceof ErrorTypeImpl ||
+                    (type instanceof DeferredType && ((DeferredType) type).getActualType() == null) ||
-               isError(type.getConstructor()));
+                    type instanceof ErrorTypeImpl ||
+                    isError(type.getConstructor())
+               );
+    }
+
+    public static boolean containsErrorType(@Nullable JetType type) {
+        if (type == null) return false;
+        if (type instanceof NamespaceType) return false;
+        if (isErrorType(type)) return true;
+        for (TypeProjection projection : type.getArguments()) {
+            if (containsErrorType(projection.getType())) return true;
+        }
+        return false;
     }
 
     public static boolean isError(@NotNull DeclarationDescriptor candidate) {

idea/src/org/jetbrains/jet/plugin/annotations/DebugInfoAnnotator.java

@@ -17,6 +17,7 @@ import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.calls.ResolvedCallImpl;
 import org.jetbrains.jet.lang.types.ErrorUtils;
+import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lexer.JetTokens;
 import org.jetbrains.jet.plugin.JetHighlighter;
 import org.jetbrains.jet.plugin.compiler.WholeProjectAnalyzerFacade;
@@ -102,7 +103,8 @@ public class DebugInfoAnnotator implements Annotator {
                         }
                         boolean resolved = target != null;
                         boolean unresolved = unresolvedReferences.contains(expression);
-                        if (declarationDescriptor != null && !ApplicationManager.getApplication().isUnitTestMode() && ErrorUtils.isError(declarationDescriptor)) {
+                        JetType expressionType = bindingContext.get(EXPRESSION_TYPE, expression);
+                        if (declarationDescriptor != null && !ApplicationManager.getApplication().isUnitTestMode() && (ErrorUtils.isError(declarationDescriptor) || ErrorUtils.containsErrorType(expressionType))) {
                             holder.createErrorAnnotation(expression, "[DEBUG] Resolved to error element").setTextAttributes(JetHighlighter.JET_RESOLVED_TO_ERROR);
                         }
                         if (resolved && unresolved) {