AIOOBE IDEA-103980

(cherry picked from commit 235e1ab6ff11856c91e6c5afded3209879ac473e)

java/java-psi-impl/src/com/intellij/psi/scope/conflictResolvers/JavaMethodsConflictResolver.java

@@ -107,6 +107,7 @@ public class JavaMethodsConflictResolver implements PsiConflictResolver{
           final PsiMethod method = (PsiMethod)conflict.getElement();
           if (method != null) {
             final PsiParameter[] methodParameters = method.getParameterList().getParameters();
+            if (methodParameters.length == 0) continue;
             final PsiParameter param = i < methodParameters.length ? methodParameters[i] : methodParameters[methodParameters.length - 1];
             final PsiType paramType = param.getType();
             if (!LambdaUtil.isAcceptable(lambdaExpression, conflict.getSubstitutor().substitute(paramType), true)) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/ConflictResolution.java

@@ -0,0 +1,12 @@
+class Demo {
+
+    public void f1() {
+        f2<error descr="'f2()' in 'Demo' cannot be applied to '(int, <lambda expression>)'">(2, input -> input)</error>;
+    }
+
+    public void f2() {
+    }
+
+    public void f2(Object... params) {
+    }
+}

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

@@ -86,6 +86,7 @@ public class LambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testVoidCompatibility() { doTest(); }
   public void testConditionalInferenceFromOppositePart() { doTest(); }
   public void testDeclaredTypeParameterBoundsAndUnboundedWildcard() { doTest(); }
+  public void testConflictResolution() throws Exception {doTest();}
 
   private void doTest() {
     doTest(false);