new inference: postpone unresolved variables in favor to variables with proper equals bound

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

@@ -1121,6 +1121,10 @@ public class InferenceSession {
           unresolved.add(var);
         }
       }
+      if (!unresolved.isEmpty() && vars.size() > unresolved.size()) {
+        vars.removeAll(unresolved);
+        vars.addAll(unresolved);
+      }
       if (!myIncorporationPhase.hasCaptureConstraints(unresolved)) {
         PsiSubstitutor firstSubstitutor = resolveSubset(vars, substitutor);
         if (hasBoundProblems(vars, firstSubstitutor)) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/graphInference/PostponeUnresolvedVariables.java

@@ -0,0 +1,13 @@
+
+import java.util.Comparator;
+import java.util.function.Supplier;
+
+class Test {
+
+
+  void f(Supplier<Comparable> m) {
+    g(m, Comparator.naturalOrder());
+  }
+  <K> void g(Supplier<K> f, Comparator<K> c) {}
+
+}

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

@@ -482,6 +482,10 @@ public class GraphInferenceHighlightingTest extends LightDaemonAnalyzerTestCase
     doTest();
   }
 
+  public void testPostponeUnresolvedVariables() throws Exception {
+    doTest();
+  }
+
   private void doTest() throws Exception {
     doTest(false);
   }