new inference: check intersection type of upper bound to detect substitution (IDEA-165011)

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

@@ -20,6 +20,7 @@ import com.intellij.psi.impl.source.resolve.graphInference.InferenceBound;
 import com.intellij.psi.impl.source.resolve.graphInference.InferenceSession;
 import com.intellij.psi.impl.source.resolve.graphInference.InferenceVariable;
 import com.intellij.psi.util.InheritanceUtil;
+import com.intellij.psi.util.PsiUtil;
 import com.intellij.psi.util.TypeConversionUtil;
 
 import java.util.HashSet;
@@ -135,6 +136,15 @@ public class StrictSubtypingConstraint implements ConstraintFormula {
           if (upperBound instanceof PsiClassType) {
             sType = (PsiClassType)upperBound;
           }
+          else if (upperBound instanceof PsiIntersectionType) {
+            for (PsiType type : ((PsiIntersectionType)upperBound).getConjuncts()) {
+              PsiClass sCandidate = PsiUtil.resolveClassInClassTypeOnly(type);
+              if (sCandidate != null && InheritanceUtil.isInheritorOrSelf(sCandidate, CClass, true)) {
+                sType = (PsiClassType)type;
+                break;
+              }
+            }
+          }
         }
 
         if (sType == null) return false;

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

@@ -0,0 +1,10 @@
+
+import java.util.List;
+
+class Test {
+  <B> void foo(final Enum<? extends List<B>> f) {}
+
+  void bar(final Enum<? extends List<String>> e) {
+    foo(e);
+  }
+}

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

@@ -495,6 +495,10 @@ public class GraphInferenceHighlightingTest extends LightDaemonAnalyzerTestCase
     doTest();
   }
 
+  public void testRecursiveTypeWithCapture() throws Exception {
+    doTest();
+  }
+
   private void doTest() throws Exception {
     doTest(false);
   }