new inference: propagate current substitutors during additional constrains processing (IDEA-118965)

java/java-psi-api/src/com/intellij/psi/LambdaUtil.java

@@ -468,12 +468,12 @@ public class LambdaUtil {
               final int finalLambdaIdx = adjustLambdaIdx(lambdaIdx, (PsiMethod)resolve, parameters);
               if (finalLambdaIdx < parameters.length) {
                 if (!tryToSubstitute) return getNormalizedType(parameters[finalLambdaIdx]);
-                if (cachedType != null && paramIdx > -1) {
+                if (cachedType != null) {
                   final PsiMethod interfaceMethod = getFunctionalInterfaceMethod(cachedType);
                   if (interfaceMethod != null) {
                     final PsiClassType.ClassResolveResult cachedResult = PsiUtil.resolveGenericsClassInType(cachedType);
-                    final PsiType interfaceMethodParameterType = interfaceMethod.getParameterList().getParameters()[paramIdx].getType();
-                    if (!dependsOnTypeParams(cachedResult.getSubstitutor().substitute(interfaceMethodParameterType), cachedType, expression)){
+                    if (!dependsOnTypeParams(paramIdx == -1 ? cachedType :
+                                             cachedResult.getSubstitutor().substitute(interfaceMethod.getParameterList().getParameters()[paramIdx].getType()), cachedType, expression)){
                       return cachedType;
                     }
                   }

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

@@ -696,7 +696,13 @@ public class InferenceSession {
 
       additionalConstraints.removeAll(subset);
 
-      PsiSubstitutor substitutor = resolveBounds(varsToResolve, mySiteSubstitutor, false);
+      PsiSubstitutor substitutor = resolveBounds(varsToResolve, mySiteSubstitutor, true);
+
+      if (myContext instanceof PsiCallExpression) {
+        PsiExpressionList argumentList = ((PsiCallExpression)myContext).getArgumentList();
+        LOG.assertTrue(argumentList != null);
+        MethodCandidateInfo.updateSubstitutor(argumentList, substitutor);
+      }
 
       for (ConstraintFormula additionalConstraint : subset) {
         additionalConstraint.apply(substitutor);

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/AdditionalConstraintSubstitution.java

@@ -0,0 +1,19 @@
+import java.util.Map;
+import java.util.function.BinaryOperator;
+import java.util.function.Function;
+import java.util.stream.Collector;
+import java.util.stream.Stream;
+
+public class Bug
+{
+
+  void foo(Stream<Bug> words){
+    words.collect(toMap(w -> 1, (a, b) -> a + b));
+  }
+
+  public static <T, K, U>
+  Collector<T, ?, Map<K,U>> toMap(Function<Bug,  U> valueMapper,
+                                  BinaryOperator<U> mergeFunction) {
+    return null;
+  }
+}

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

@@ -83,7 +83,7 @@ public class LambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testAmbiguityReturnValueResolution3() { doTest(); }
   public void testLambdaOnVarargsPlace1() { doTest(); }
   public void testInferenceFromSecondLambda() { doTest(); }
-  public void _testAcceptRawSubstForLambda() { doTest(); }
+  public void testAcceptRawSubstForLambda() { doTest(); }
   public void testCheckFunctionalInterfaceAccess() { doTest(); }
   public void testVoidCompatibility() { doTest(); }
   public void testConditionalInferenceFromOppositePart() { doTest(); }

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

@@ -107,6 +107,10 @@ public class NewLambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testAdditionalConstraintSubstitution() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }