overload resolution: ensure all list of parameters is checked during most specific check of varargs methods (IDEA-150224)

java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java

@@ -1506,7 +1506,7 @@ public class InferenceSession {
       LOG.assertTrue(parameters1.length == parameters2.length);
     }
 
-    final int paramsLength = !varargs ? parameters1.length : parameters1.length - 1;
+    final int paramsLength = !varargs ? parameters1.length : Math.max(parameters1.length, parameters2.length) - 1;
     for (int i = 0; i < paramsLength; i++) {
       PsiType sType = getParameterType(parameters1, i, siteSubstitutor1, false);
       PsiType tType = session.substituteWithInferenceVariables(getParameterType(parameters2, i, siteSubstitutor1, varargs));

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/overloadResolution/LongerParamsWhenVarargs.java

@@ -0,0 +1,21 @@
+interface Node<<warning descr="Type parameter 'T' is never used">T</warning>> {
+
+  @SafeVarargs
+  static <T> Node<T> of(T value, Node<T>... children) {
+    System.out.println(value);
+    System.out.println(children);
+    return null;
+  }
+
+
+  @SafeVarargs
+  static <T1> Node<T1> of(T1... values) {
+    System.out.println(values);
+    return null;
+  }
+
+  static void test() {
+    Node.of(1, Node.of(2), Node.of(3));
+    Node.<Integer>of(1, Node.<Integer>of(2), Node.<Integer> of(3));
+  }
+}

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

@@ -195,6 +195,10 @@ public class OverloadResolutionTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testLongerParamsWhenVarargs() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(true);
   }