by-instance equality in lookup

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

@@ -735,7 +735,7 @@ public class Bar {
     assert !lookup
   }
 
-  public void testExplicitlyAutocompletionAfterAutoPopup() {
+  public void testExplicitAutocompletionAfterAutoPopup() {
     myFixture.configureByText 'a.java', 'class Foo <caret>'
     type 'ext'
 
@@ -746,5 +746,22 @@ public class Bar {
     myFixture.checkResult 'class Foo extends <caret>'
   }
 
+  public void testExplicitMultipleVariantCompletionAfterAutoPopup() {
+    myFixture.configureByText 'a.java', 'class Foo {<caret>}'
+    type 'pr'
+
+    CompletionAutoPopupHandler.ourTestingAutopopup = false
+    edt {
+      myFixture.completeBasic()
+    }
+    myFixture.checkResult 'class Foo {pr<caret>}'
+    lookup.items.each {
+      lookup.list.cellRenderer.getListCellRendererComponent(lookup.list, it, 0, false, false)
+    }
+    assert myFixture.lookupElementStrings == ['private', 'protected']
+  }
+
+
+
 
 }

platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java

@@ -64,6 +64,7 @@ import com.intellij.util.containers.ConcurrentHashMap;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.ui.AsyncProcessIcon;
 import com.intellij.util.ui.ButtonlessScrollBarUI;
+import gnu.trove.THashSet;
 import gnu.trove.TObjectHashingStrategy;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -382,7 +383,8 @@ public class LookupImpl extends LightweightHint implements LookupEx, Disposable
 
     final List<LookupElement> items = matchingItems(snapshot);
 
-    if (items.equals(getItems())) {
+    List<LookupElement> oldItems = getItems();
+    if (oldItems.size() == items.size() && new THashSet<LookupElement>(items, TObjectHashingStrategy.IDENTITY).containsAll(oldItems)) {
       return;
     }