navigate to several elements if there are many

(not only in ambiguity case)

idea/src/org/jetbrains/jet/plugin/references/JetPsiReference.java

@@ -130,6 +130,10 @@ public abstract class JetPsiReference implements PsiPolyVariantReference {
                 .getBindingContext();
         Collection<? extends DeclarationDescriptor> declarationDescriptors = bindingContext.get(AMBIGUOUS_REFERENCE_TARGET, myExpression);
         if (declarationDescriptors == null) {
+            List<PsiElement> psiElements = BindingContextUtils.resolveToDeclarationPsiElements(bindingContext, myExpression);
+            if (!psiElements.isEmpty()) {
+                return PsiElementResolveResult.createResults(psiElements);
+            }
             List<PsiElement> standardLibraryElements = resolveStandardLibrarySymbol(bindingContext);
             if (!standardLibraryElements.isEmpty()) {
                 return PsiElementResolveResult.createResults(standardLibraryElements);

idea/testData/resolve/SeveralOverrides.kt

@@ -0,0 +1,15 @@
+trait A {
+    fun foo()
+}
+
+trait B {
+    fun foo()
+}
+
+trait C : A, B {
+
+}
+
+fun test(c: C) {
+    c.<caret>foo()
+}

idea/tests/org/jetbrains/jet/resolve/ResolveBaseTest.java

@@ -17,6 +17,7 @@
 package org.jetbrains.jet.resolve;
 
 import com.intellij.openapi.projectRoots.Sdk;
+import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiPolyVariantReference;
 import com.intellij.psi.PsiReference;
 import com.intellij.psi.ResolveResult;
@@ -78,10 +79,12 @@ public class ResolveBaseTest extends LightCodeInsightTestCase {
 
         final PsiPolyVariantReference variantReference = (PsiPolyVariantReference) psiReference;
 
+        PsiElement element = variantReference.resolve();
         final ResolveResult[] results = variantReference.multiResolve(true);
         for (ResolveResult result : results) {
             assertNotNull(result);
         }
+        assertTrue("Nothing resolved by reference '" + psiReference.getElement().getText() + "'.", element != null || results.length > 0);
     }
 
     @NotNull