extract method: do not declare variables after call with local class defined in extracted method (IDEA-46775)

java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java

@@ -419,6 +419,13 @@ public class ExtractMethodProcessor implements MatchProvider {
       if (!remainingReferences.isEmpty()) {
         throw new PrepareFailedException("Cannot extract method because the selected code fragment defines local classes used outside of the fragment", remainingReferences.get(0));
       }
+      if (classExtracted) {
+        for (PsiVariable variable : myControlFlowWrapper.getUsedVariables()) {
+          if (isDeclaredInside(variable) && !variable.equals(myOutputVariable) && PsiUtil.resolveClassInType(variable.getType()) == localClass) {
+            throw new PrepareFailedException("Cannot extract method because the selected code fragment defines variable of local class type used outside of the fragment", variable);
+          }
+        }
+      }
     }
   }
 

java/java-tests/testData/refactoring/extractMethod/LocalClassDefinedInMethodWhichIsUsedLater.java

@@ -0,0 +1,8 @@
+class Test {
+  void foo() {
+    <selection>class X {}
+    X x;
+    </selection>
+    x = null;
+  }
+}

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

@@ -338,6 +338,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testLocalClassDefinedInMethodWhichIsUsedLater() throws Exception {
+    doPrepareErrorTest("Cannot extract method because the selected code fragment defines variable of local class type used outside of the fragment");
+  }
+
   public void testForceBraces() throws Exception {
     final CodeStyleSettings settings = CodeStyleSettingsManager.getSettings(getProject());
     int old = settings.IF_BRACE_FORCE;