IDEA-175681 Duplicate "void" suggestion

java/java-impl/src/com/intellij/codeInsight/completion/MethodReturnTypeProvider.java

@@ -60,7 +60,7 @@ class MethodReturnTypeProvider extends CompletionProvider<CompletionParameters>
       @Nullable
       @Override
       public PsiType visitType(PsiType type) {
-        if (myProcessed.add(type)) {
+        if (!(type instanceof PsiPrimitiveType) && myProcessed.add(type)) {
           int priority = type.equalsToText(CommonClassNames.JAVA_LANG_OBJECT) ? 1 : 1000 - myProcessed.size();
           consumer.consume(PrioritizedLookupElement.withPriority(PsiTypeLookupItem.createLookupItem(type, position), priority));
         }

java/java-tests/testData/codeInsight/completion/normal/NoExpectedVoidReturnTypeDuplication.java

@@ -0,0 +1,5 @@
+class Foo {
+    voi<caret>d foo() {
+        return;
+    }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy

@@ -678,6 +678,10 @@ public class ListUtils {
     configure()
     assert myFixture.lookupElementStrings == ['boolean', 'byte']
   }
+  void testNoExpectedVoidReturnTypeDuplication() {
+    configure()
+    assert myFixture.lookupElementStrings == ['void']
+  }
 
   void testMethodReturnType() throws Throwable {
     doTest()