adding test of error when exporting marked subtree with code blocks

testing/examples/babel.org

@@ -159,3 +159,18 @@
 #+begin_src example-lang :session     :results output :var num=9
   the body
 #+end_src
+* conflicting blocks on export
+  :PROPERTIES:
+  :ID:       5daa4d03-e3ea-46b7-b093-62c1b7632df3
+  :END:
+#+results: a-list
+- a
+- b
+- c
+
+#+begin_src emacs-lisp :results wrap :exports both
+    "code block results"
+#+end_src
+#+begin_src emacs-lisp :var lst=a-list :results list
+  (reverse lst)
+#+end_src

testing/lisp/test-ob-exp.el

@@ -95,6 +95,11 @@ elements in the final html."
       (should (string-match "<pre.*>[^\000]*</pre>" html))
       (should (string-match "<table.*>[^\000]*</table>" html)))))
 
+(ert-deftest ob-exp/export-subtree ()
+  (org-test-at-id "5daa4d03-e3ea-46b7-b093-62c1b7632df3"
+    (org-mark-subtree)
+    (org-export-as-latex nil)))
+
 (provide 'test-ob-exp)
 
 ;;; test-ob-exp.el ends here