push down: conflict if move static to local (IDEA-182514)

java/java-impl/src/com/intellij/refactoring/memberPushDown/PushDownConflicts.java

@@ -21,6 +21,7 @@ import com.intellij.psi.*;
 import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.psi.util.InheritanceUtil;
 import com.intellij.psi.util.MethodSignatureUtil;
+import com.intellij.psi.util.PsiUtil;
 import com.intellij.refactoring.RefactoringBundle;
 import com.intellij.refactoring.util.CommonRefactoringUtil;
 import com.intellij.refactoring.util.RefactoringConflictsUtil;
@@ -203,6 +204,12 @@ public class PushDownConflicts {
         }
       }
     }
+
+    if (movedMember.hasModifierProperty(PsiModifier.STATIC) &&
+        PsiUtil.getEnclosingStaticElement(targetClass, null) == null &&
+        !(targetClass.getParent() instanceof PsiFile)) {
+      myConflicts.putValue(movedMember, "Static " + RefactoringUIUtil.getDescription(movedMember, false) + " can't be pushed to non-static " + RefactoringUIUtil.getDescription(targetClass, false));
+    }
   }
 
   private class UsedMovedMembersConflictsCollector extends ClassMemberReferencesVisitor {

java/java-tests/testData/refactoring/pushDown/StaticToLocal.java

@@ -0,0 +1,9 @@
+class Foo {
+  public static void f<caret>oo() {
+
+  }
+
+  void m() {
+    class FooExt extends Foo { }
+  }
+}

java/java-tests/testData/refactoring/pushDown/StaticToLocal_after.java

@@ -0,0 +1,9 @@
+class Foo {
+  public static void f<caret>oo() {
+
+  }
+
+  void m() {
+    class FooExt extends Foo { }
+  }
+}

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

@@ -121,6 +121,12 @@ public class PushDownTest extends LightRefactoringTestCase {
     });
   }
 
+  public void testStaticToLocal() {
+    doTest(conflicts -> {
+      assertSameElements(conflicts.values(), Collections.singletonList("Static method <b><code>foo()</code></b> can't be pushed to non-static class <b><code>FooExt</code></b>"));
+    });
+  }
+
   private void doTest() {
     doTest(false);
   }