IDEA-57403 Completion cannot suggest members of an intersection type

java/java-impl/src/com/intellij/psi/scope/util/PsiScopesUtil.java

@@ -117,6 +117,10 @@ public class PsiScopesUtil {
         substitutor = substitutor.put(arrayTypeParameters[0], ((PsiArrayType)type).getComponentType());
       }
       arrayClass.processDeclarations(processor, ResolveState.initial().put(PsiSubstitutor.KEY, substitutor), arrayClass, place);
+    } else if (type instanceof PsiIntersectionType) {
+      for (PsiType psiType : ((PsiIntersectionType)type).getConjuncts()) {
+        processTypeDeclarations(psiType, place, processor);
+      }
     } else {
       final JavaResolveResult result = PsiUtil.resolveGenericsClassInType(type);
       final PsiClass clazz = (PsiClass)result.getElement();

java/java-tests/testData/codeInsight/completion/normal/IntersectionTypeMembers.java

@@ -0,0 +1,18 @@
+interface IA{
+    void fooa();
+}
+
+interface IB{
+    void foob();
+}
+
+interface IC<T extends IA>{
+    T c();
+}
+
+class K {
+    void foo(IC<? extends IB> x){
+        x.c().fo<caret>
+
+    }
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy

@@ -786,6 +786,11 @@ public class NormalCompletionTest extends LightFixtureCompletionTestCase {
     checkResultByFile(getTestName(false) + "_after.java")
   }
 
+  public void testIntersectionTypeMembers() throws Throwable {
+    configure()
+    assertStringItems "fooa", "foob"
+  }
+
   public void testCastInstanceofedQualifier() throws Throwable { doTest(); }
   public void testCastComplexInstanceofedQualifier() throws Throwable { doTest(); }