Fix TempDir not working for inherited fields

fixes #1229

Author: leonard84

spock-core/src/main/java/org/spockframework/runtime/extension/builtin/TempDirExtension.java

@@ -2,9 +2,7 @@
 
 import org.spockframework.runtime.InvalidSpecException;
 import org.spockframework.runtime.extension.IAnnotationDrivenExtension;
-import org.spockframework.runtime.model.FeatureInfo;
-import org.spockframework.runtime.model.FieldInfo;
-import org.spockframework.runtime.model.SpecInfo;
+import org.spockframework.runtime.model.*;
 import org.spockframework.tempdir.TempDirConfiguration;
 import org.spockframework.util.Beta;
 import spock.lang.TempDir;
@@ -33,7 +31,7 @@ public void visitFieldAnnotation(TempDir annotation, FieldInfo field) {
     if (field.isShared()) {
       specInfo.addInterceptor(interceptor);
     } else {
-      for (FeatureInfo featureInfo : specInfo.getAllFeatures()) {
+      for (FeatureInfo featureInfo : specInfo.getBottomSpec().getAllFeatures()) {
         featureInfo.addIterationInterceptor(interceptor);
       }
     }

spock-specs/src/test/groovy/org/spockframework/smoke/extension/TempDirExtensionSpec.groovy

@@ -1,13 +1,9 @@
 package org.spockframework.smoke.extension
 
 import org.spockframework.EmbeddedSpecification
-import spock.lang.Shared
-import spock.lang.Stepwise
-import spock.lang.TempDir
+import spock.lang.*
 
-import java.nio.file.Files
-import java.nio.file.Path
-import java.nio.file.Paths
+import java.nio.file.*
 
 /**
  * @author dqyuan
@@ -121,3 +117,15 @@ def method1() {
   }
 
 }
+
+abstract class TempDirBaseSpec extends Specification {
+  @TempDir Path tmp
+}
+
+@Issue("https://github.com/spockframework/spock/issues/1229")
+class TempDirInheritedSpec extends TempDirBaseSpec {
+  void "TempDir works for inherited fields"() {
+    expect:
+    tmp != null
+  }
+}