Make inserting whitespaces around checklist a bit more intelligent

Not quite sure yet whether this is really it, and maybe it would be better to
create some new utility functions to ensure enough blank lines before and after
point.  But let's try it out first and fix it later.

site-lisp/db-org.el

@@ -939,7 +939,14 @@ inserting the checklist."
                number-of-backlinks
                point-before-backlinks)
 
-           (insert (format "\nRelevant backlinks (%s):\n\n"
+           ;; Insert blank line, but only if the previous line is not blank
+           ;; already.
+           (unless (save-mark-and-excursion
+                     (forward-line -1)
+                     (looking-at (rx bol (* space) eol)))
+             (insert "\n"))
+
+           (insert (format "Relevant backlinks (%s):\n\n"
                            (if parent-depth
                                (format "parent-depth %d" parent-depth)
                              "all parents")))
@@ -970,7 +977,6 @@ inserting the checklist."
            (insert "\n\nTemplate:")
            (if (not template-marker)
                (insert " none.")
-             (insert "\n")
              (db/org-copy-body-from-item-to-point template-marker))))))
 
 (define-obsolete-function-alias 'db/org-copy-template
@@ -996,7 +1002,8 @@ determined."
 This can be used to copy checklists from templates to the current
 item, which might be an instance of a periodic task.  If POM is
 not given, use `db/org-get-location' to interactively query for
-it.  Adds newline before and after the template."
+it.  Ensures that there are newlines before and after the
+inserted template."
   (interactive (list (db/org-get-location t)))
   (unless (number-or-marker-p pom)
     (user-error "Argument is neither point nor mark: %s" pom))
@@ -1024,9 +1031,26 @@ it.  Adds newline before and after the template."
                           (user-error "Cannot find content in template, or content is empty"))
                         (string-trim-right
                          (buffer-substring-no-properties content-begin content-end)))))))))
-    (insert "\n")
+
+    (cond
+     ;; Open next line if the current line is not blank
+     ((not (looking-at (rx bol eol)))
+      (insert "\n\n"))
+
+     ;; Add newline, but only if the previous line is not blank already.
+     ((not (save-mark-and-excursion
+             (forward-line -1)
+             (looking-at (rx bol (* space) eol))))
+      (insert "\n")))
+
     (insert body)
-    (insert "\n")
+
+    ;; Insert final newline, but only when no blank line follows.
+    (unless (save-mark-and-excursion
+              (forward-line 1)
+              (looking-at (rx bol (* space) eol)))
+      (insert "\n"))
+
     (org-update-statistics-cookies nil)))
 
 (defun db/org-update-headline-log-note (&optional new-headline)