move to inner: ignore package local access if class was moved to interface (IDEA-39296)

java/java-impl/src/com/intellij/refactoring/move/moveClassesOrPackages/MoveClassToInnerProcessor.java

@@ -353,7 +353,7 @@ public class MoveClassToInnerProcessor extends BaseRefactoringProcessor {
   private boolean isInaccessibleFromTarget(final PsiElement element, final String visibility) {
     final PsiPackage elementPackage = JavaDirectoryService.getInstance().getPackage(element.getContainingFile().getContainingDirectory());
     return !PsiUtil.isAccessible(myTargetClass, element, null) ||
-        (visibility.equals(PsiModifier.PACKAGE_LOCAL) && !Comparing.equal(elementPackage, myTargetPackage));
+        (!myTargetClass.isInterface() && visibility.equals(PsiModifier.PACKAGE_LOCAL) && !Comparing.equal(elementPackage, myTargetPackage));
   }
 
   private void detectInaccessibleMemberUsages(final ConflictsCollector collector) {

java/java-tests/testData/refactoring/moveClassToInner/locallyUsedPackageLocalToPublicInterface/after/pack1/Usage.java

@@ -0,0 +1,7 @@
+package pack1;
+
+import pack2.A;
+
+class Usage {
+  A.Class1 cl1;
+}

java/java-tests/testData/refactoring/moveClassToInner/locallyUsedPackageLocalToPublicInterface/after/pack2/A.java

@@ -0,0 +1,6 @@
+package pack2;
+
+public interface A {
+    static class Class1 {
+    }
+}

java/java-tests/testData/refactoring/moveClassToInner/locallyUsedPackageLocalToPublicInterface/before/pack1/Class1.java

@@ -0,0 +1,4 @@
+package pack1;
+
+class Class1 {
+}

java/java-tests/testData/refactoring/moveClassToInner/locallyUsedPackageLocalToPublicInterface/before/pack1/Usage.java

@@ -0,0 +1,4 @@
+package pack1;
+class Usage {
+  Class1 cl1;
+}

java/java-tests/testData/refactoring/moveClassToInner/locallyUsedPackageLocalToPublicInterface/before/pack2/A.java

@@ -0,0 +1,4 @@
+package pack2;
+
+public interface A {
+}

java/java-tests/testSrc/com/intellij/refactoring/MoveClassToInnerTest.java

@@ -79,6 +79,10 @@ public class MoveClassToInnerTest extends CodeInsightTestCase {
     doTest(new String[] { "pack1.Class1" }, "pack1.A");
   }
 
+  public void testLocallyUsedPackageLocalToPublicInterface() throws Exception {
+    doTest(new String[]{"pack1.Class1"}, "pack2.A");
+  }
+
   public void testPackageLocalClass() throws Exception {
     doTestConflicts("pack1.Class1", "pack2.A", "Field <b><code>Class1.c2</code></b> uses a package-local class <b><code>pack1.Class2</code></b>.");
   }