new inference: String::length should be exact (IDEA-122191)

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

@@ -163,7 +163,7 @@ public class PsiMethodReferenceExpressionImpl extends PsiReferenceExpressionBase
     if (containingClass != null) {
       PsiMethod[] methods = null;
       if (element instanceof PsiIdentifier) {
-        methods = containingClass.findMethodsByName(element.getText(), true);
+        methods = containingClass.findMethodsByName(element.getText(), !qualifierResolveResult.isReferenceTypeQualified());
       }
       else if (isConstructor()) {
         final PsiElementFactory factory = JavaPsiFacade.getElementFactory(getProject());

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newMethodRef/IDEA112191.java

@@ -0,0 +1,15 @@
+import java.util.function.ToIntFunction;
+class Test {
+  {
+    fooBar(String::length);
+  }
+
+  class Foo<K> {
+    Foo<K> then() {
+      return null;
+    }
+  }
+  static <T> Foo<T> fooBar(ToIntFunction<? super T> keyExtractor) {
+    return null;
+  }
+}

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

@@ -209,6 +209,10 @@ public class NewMethodRefHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testIDEA112191() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }