overload resolution: N parameters of varargs target should be less than N parameters of corresponding interface (IDEA-257526)

GitOrigin-RevId: 811135c478f3f98fa1923f4b58c27d6ca0144939

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiMethodReferenceExpressionImpl.java

@@ -88,18 +88,24 @@ public class PsiMethodReferenceExpressionImpl extends JavaStubPsiElement<Functio
         final boolean isStatic = ((PsiMethod)element).hasModifierProperty(PsiModifier.STATIC);
         final int parametersCount = ((PsiMethod)element).getParameterList().getParametersCount();
         if (qualifierResolveResult.isReferenceTypeQualified() && getReferenceNameElement() instanceof PsiIdentifier) {
-          if (parametersCount == interfaceArity && isStatic) {
+          int offset = isStatic ? 0 : 1;
+          if (parametersCount == interfaceArity - offset) {
             return true;
           }
-          if (parametersCount == interfaceArity - 1 && !isStatic) {
-            return true;
+          if (((PsiMethod)element).isVarArgs()) {
+            if (interfaceMethod.isVarArgs()) {
+              return true;
+            }
+            return interfaceArity >= parametersCount + offset - 1;
           }
-          if (((PsiMethod)element).isVarArgs()) return true;
         }
         else if (!isStatic) {
-          if (parametersCount == interfaceArity || ((PsiMethod)element).isVarArgs()) {
+          if (parametersCount == interfaceArity) {
             return true;
           }
+          if (((PsiMethod)element).isVarArgs()) {
+            return interfaceMethod.isVarArgs() || interfaceArity >= parametersCount - 1 ;
+          }
         }
       } else if (element instanceof PsiClass) {
         return true;

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

@@ -0,0 +1,60 @@
+
+interface I {
+  void foo(String s, Object... params);
+}
+
+class Foo {
+  void n(I i) {}
+  void n(Runnable r) {}
+  void fooBar(String s, Object... params) {}
+  {
+    n(this::fooBar);
+  }
+}
+
+
+class Foo1 {
+  void n(I i) {}
+  void n(Runnable r) {}
+  static void fooBar(String s, Object... params) {}
+  {
+    n(Foo1::fooBar);
+  }
+}
+
+
+interface I2 {
+  void foo(Foo2 s, Object... params);
+}
+
+class Foo2 {
+  void n(I2 i) {}
+  void n(Runnable r) {}
+  void fooBar(Object... params) {}
+  {
+    n(Foo2::fooBar);
+  }
+
+  void fooBar1(Object o, Object... params) {}
+  {
+    n(Foo2::fooBar1);
+  }
+}
+
+
+class Foo3 {
+  interface I3 {
+    void foo(Foo3 s, Object... params);
+  }
+
+  interface I4 {
+    void foo(Object params);
+  }
+
+  void n(I3 i) {}
+  void n(I4 r) {}
+  void fooBar(Object o, Object... params) {}
+  {
+    n(Foo3::fooBar);
+  }
+}

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

@@ -280,6 +280,7 @@ public class OverloadResolutionTest extends LightDaemonAnalyzerTestCase {
   public void testFixedContainingClassTypeArguments() { doTest(false);}
   public void testPotentialCompatibilityWithArrayCreation() { doTest(false);}
   public void testOverloadsWithOneNonCompatible() { doTest(false);}
+  public void testTwoFunctionalInterfacesWithVarargs() { doTest(false);}
   public void testSecondSearchOverloadsBoxing() {
     IdeaTestUtil.setTestVersion(JavaSdkVersion.JDK_1_8, getModule(), getTestRootDisposable());
     String filePath = BASE_PATH + "/" + getTestName(false) + ".java";