method refs: varargs methods should be checked for parameter numbers (IDEA-133173)

java/java-psi-api/src/com/intellij/psi/PsiMethodReferenceUtil.java

@@ -94,7 +94,7 @@ public class PsiMethodReferenceUtil {
         return false;
       }
     }
-    return true;
+    return !varargs || parameterTypes.length - 1 <= argTypes.length - offset;
   }
 
   @NotNull

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newMethodRef/VarargsParametersCountComparison.java

@@ -0,0 +1,14 @@
+import java.util.stream.Stream;
+
+class A {
+  private void test5(Integer i, String... strings) {}
+  private void <warning descr="Private method 'test5(java.lang.Integer, java.lang.Integer, java.lang.String...)' is never used">test5</warning>(Integer i, Integer b, String... strings) {
+    System.out.println(i);
+    System.out.println(b);
+    System.out.println(strings);
+  }
+
+  void p(Stream<Integer> stream){
+    stream.forEach(this::test5);
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewMethodRefHighlightingTest.java

@@ -330,6 +330,10 @@ public class NewMethodRefHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testVarargsParametersCountComparison() throws Exception {
+    doTest(true);
+  }
+
   private void doTest() {
     doTest(false);
   }