new inference: lift type params from referenced method

(cherry picked from commit 057bd4d4d576711b77141b64987079ef8d59a583)

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

@@ -239,7 +239,7 @@ public class InferenceSession {
     return mySiteSubstitutor;
   }
 
-  private void initBounds(PsiTypeParameter... typeParameters) {
+  public void initBounds(PsiTypeParameter... typeParameters) {
     for (PsiTypeParameter parameter : typeParameters) {
       if (myInferenceVariables.containsKey(parameter)) continue;
       InferenceVariable variable = new InferenceVariable(parameter);

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

@@ -154,6 +154,7 @@ public class PsiMethodReferenceCompatibilityConstraint implements ConstraintForm
         return false;
       }
  
+      session.initBounds(method.getTypeParameters());
       constraints.add(new TypeCompatibilityConstraint(returnType, referencedMethodReturnType));
     }
     

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

@@ -0,0 +1,18 @@
+import java.util.List;
+
+class Test {
+
+    interface Function<K, V> {
+        V _(K k);
+    }
+
+    static {
+        foo(Test::asList);
+    }
+
+    public static <T> List<T> asList(T... a) {
+        return null;
+    }
+
+    public static <C> void foo(Function<String, C> fn) {  }
+}

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

@@ -104,6 +104,10 @@ public class NewMethodRefHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testLiftMethodReferenceTypeParams() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }