org-element: Fix item interpreter when item doesn't start with a paragraph

* contrib/lisp/org-element.el (org-element-item-interpreter): Fix item
  interpreter when item doesn't start with a paragraph.
* testing/lisp/test-org-element.el: Add test.

contrib/lisp/org-element.el

@@ -684,7 +684,10 @@ CONTENTS is the contents of the element."
 	 (tag (let ((tag (org-element-property :tag item)))
 		(and tag (org-element-interpret-data tag))))
 	 ;; Compute indentation.
-	 (ind (make-string (length bullet) 32)))
+	 (ind (make-string (length bullet) 32))
+	 (item-starts-with-par-p
+	  (eq (org-element-type (car (org-element-contents item)))
+	      'paragraph)))
     ;; Indent contents.
     (concat
      bullet
@@ -694,8 +697,10 @@ CONTENTS is the contents of the element."
       ((eq checkbox 'off) "[ ] ")
       ((eq checkbox 'trans) "[-] "))
      (and tag (format "%s :: " tag))
-     (org-trim
-      (replace-regexp-in-string "\\(^\\)[ \t]*\\S-" ind contents nil nil 1)))))
+     (let ((contents (replace-regexp-in-string
+		      "\\(^\\)[ \t]*\\S-" ind contents nil nil 1)))
+       (if item-starts-with-par-p (org-trim contents)
+	 (concat "\n" contents))))))
 
 
 ;;;; Plain List

testing/lisp/test-org-element.el

@@ -1551,26 +1551,31 @@ Outside list"
 
 (ert-deftest test-org-element/plain-list-interpreter ()
   "Test plain-list and item interpreters."
-  ;; 1. Unordered list.
-  (should (equal (org-test-parse-and-interpret "- item 1") "- item 1\n"))
-  ;; 2. Description list.
-  (should
-   (equal (org-test-parse-and-interpret "- tag :: desc") "- tag :: desc\n"))
-  ;; 3. Ordered list.
-  (should
-   (equal (let ((org-plain-list-ordered-item-terminator t))
-	    (org-test-parse-and-interpret "1. Item"))
-	  "1. Item\n"))
-  ;; 4. Ordered list with counter.
-  (should
-   (equal (let ((org-plain-list-ordered-item-terminator t))
-	    (org-test-parse-and-interpret "1. [@5] Item"))
-	  "5. [@5] Item\n"))
-  ;; 5. List with check-boxes.
-  (should
-   (equal (org-test-parse-and-interpret
-	   "- [-] Item 1\n  - [X] Item 2\n  - [ ] Item 3")
-	  "- [-] Item 1\n  - [X] Item 2\n  - [ ] Item 3\n")))
+  (let ((org-list-two-spaces-after-bullet-regexp nil))
+    ;; 1. Unordered list.
+    (should (equal (org-test-parse-and-interpret "- item 1") "- item 1\n"))
+    ;; 2. Description list.
+    (should
+     (equal (org-test-parse-and-interpret "- tag :: desc") "- tag :: desc\n"))
+    ;; 3. Ordered list.
+    (should
+     (equal (let ((org-plain-list-ordered-item-terminator t))
+	      (org-test-parse-and-interpret "1. Item"))
+	    "1. Item\n"))
+    ;; 4. Ordered list with counter.
+    (should
+     (equal (let ((org-plain-list-ordered-item-terminator t))
+	      (org-test-parse-and-interpret "1. [@5] Item"))
+	    "5. [@5] Item\n"))
+    ;; 5. List with check-boxes.
+    (should
+     (equal (org-test-parse-and-interpret
+	     "- [-] Item 1\n  - [X] Item 2\n  - [ ] Item 3")
+	    "- [-] Item 1\n  - [X] Item 2\n  - [ ] Item 3\n"))
+    ;; 6. Item not starting with a paragraph.
+    (should
+     (equal (org-test-parse-and-interpret "-\n  | a | b |")
+	    "- \n  | a | b |\n"))))
 
 (ert-deftest test-org-element/quote-block-interpreter ()
   "Test quote block interpreter."