java completion sorting: disprefer return in void lambdas (IDEA-CR-9303, IDEA-152289)

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

@@ -271,6 +271,10 @@ public class PreferByKindWeigher extends LookupElementWeigher {
       if (parent instanceof PsiMethod) {
         return ((PsiMethod)parent).isConstructor() || PsiType.VOID.equals(((PsiMethod)parent).getReturnType());
       }
+      if (parent instanceof PsiLambdaExpression) {
+        PsiMethod method = LambdaUtil.getFunctionalInterfaceMethod(((PsiLambdaExpression)parent).getFunctionalInterfaceType());
+        return method != null && PsiType.VOID.equals(method.getReturnType());
+      }
     }
     return false;
   }

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

@@ -0,0 +1,8 @@
+class Util {
+  int foo(int reaction, boolean rezet) {
+    Runnable r = () -> {
+      re<caret>
+    };
+  }
+
+}

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

@@ -442,6 +442,9 @@ interface TxANotAnno {}
   public void testDispreferReturnInVoidMethodTopLevel() {
     checkPreferredItems 0, 'reaction', 'rezet', 'return'
   }
+  public void testDispreferReturnInVoidLambda() {
+    checkPreferredItems 0, 'reaction', 'rezet', 'return'
+  }
 
   public void testDoNotPreferGetClass() {
     checkPreferredItems 0, 'get', 'getClass'