IDEA-109171 Code completion is suggesting to implement a class

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

@@ -68,7 +68,7 @@ public class JavaCompletionSorting {
     CompletionSorter sorter = CompletionSorter.defaultSorter(parameters, result.getPrefixMatcher());
     if (!smart && afterNew) {
       sorter = sorter.weighBefore("liftShorter", new PreferExpected(true, expectedTypes));
-    } else {
+    } else if (PsiTreeUtil.getParentOfType(position, PsiReferenceList.class) == null) {
       sorter = ((CompletionSorterImpl)sorter).withClassifier("liftShorterClasses", true, new LiftShorterClasses(position));
     }
     if (smart) {

java/java-tests/testData/codeInsight/completion/normalSorting/PreferInterfacesInImplements.java

@@ -1,8 +1,6 @@
 interface FooIntf {}
 class FooClass {}
+class Foo {}
 
-class Goo implements Foo<caret> {
-    int boo() {}
-    int doo() {}
-    int foo() {}
+class Goo implements Fo<caret> {
 }

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

@@ -257,7 +257,7 @@ public class NormalCompletionOrderingTest extends CompletionSortingTestCase {
   }
 
   public void testPreferInterfacesInImplements() {
-    checkPreferredItems(0, "FooIntf", "FooClass");
+    checkPreferredItems(0, "FooIntf", "Foo", "FooClass");
   }
 
   public void testPreferClassesInExtends() {