Refactor org link formatting functions to avoid duplicate code

They will show as links in links and will thus be mostly incomprehensible.

site-lisp/db-org.el

@@ -882,14 +882,20 @@ item using `db/org-get-location', which see."
                                    (db/org-get-location)))
            (list (org-id-get) (org-entry-get nil "CUSTOM_ID")))))
 
-(defun db/org-insert-link-to-pom (pom)
-  "Insert an Org link to headline at POM.
+(defun db/org--format-link-from-pom (pom)
+  "Return Org link pointing to Org item at POM.
+
+POM must be point or mark to a valid Org item.  The link will be
+of the format [[id][item-headline]], where `id' is the value of
+the ID property of the item.  If the item does not have such a
+property, is is generated automatically.
+
+If `item-headline' contains any links itself, those will be
+replaced by the description when available, and otherwise by
+their plain link part."
+  (unless (or (markerp pom) (integerp pom))
+    (user-error "POM must be point or mark"))
 
-If headline consists of a link with description, only the
-description of that link will be included in the description of
-the newly inserted link instead of the complete headline.  This
-avoids containing a link in the description of the newly inserted
-link."
   (let (item id)
     (org-with-point-at pom
       (setq item (org-entry-get (point) "ITEM")
@@ -905,7 +911,24 @@ link."
                              desc
                              (substring item (match-end 0)))))))
 
-    (org-insert-link nil (format "id:%s" id) item)))
+    (org-link-make-string (format "id:%s" id) item)))
+
+(defun db/org--format-link-from-org-id (id)
+  "Format ID as an Org mode link [[ID][item-headline]].
+
+If the headline of the item pointed to by ID contains any links,
+those are replaced by their description before formatting."
+  (db/org--format-link-from-pom (org-id-find id 'marker)))
+
+(defun db/org-insert-link-to-pom (pom)
+  "Insert an Org link to headline at POM.
+
+If headline consists of a link with description, only the
+description of that link will be included in the description of
+the newly inserted link instead of the complete headline.  This
+avoids containing a link in the description of the newly inserted
+link."
+  (insert (db/org--format-link-from-pom pom)))
 
 (defun db/org-add-link-to-other-item (arg)
   "Interactively query for item and add link to it at point.
@@ -1012,11 +1035,6 @@ level/position comes first)."
           (push (point-marker) parent-markers))
         parent-markers))))
 
-(defun db/org--format-link-with-headline (id)
-  "Format ID as an Org mode link [[ID][item headline]]."
-  (org-link-make-string (format "id:%s" id)
-                        (org-entry-get (org-id-find id 'marker) "ITEM")))
-
 (defun org-dblock-write:db/org-backlinks (params)
   "Write table of backlinks for current item and its parent items as Org table.
 
@@ -1046,16 +1064,16 @@ PARAMS may contain the following values:
     ;; Formatting.
     (insert (format "| Item | Backlinks | Priority |\n|---|"))
     (dolist (headline headlines)
-      (insert (format "\n| %s |\n|---|" (db/org--format-link-with-headline (car headline))))
+      (when (cdr headline)           ; do not print backlinks if there are none
+        (insert (format "\n| %s |\n|---|" (db/org--format-link-from-org-id (car headline))))
         (let ((backlink-lines (-> (mapcar #'(lambda (backlink-id)
-                                            (list (db/org--format-link-with-headline backlink-id)
+                                              (list (db/org--format-link-from-org-id backlink-id)
                                                     (org-entry-get (org-id-find backlink-id 'marker)
                                                                    "PRIORITY")))
                                           (cdr headline))
                                   (cl-sort #'string< :key #'cl-second))))
           (dolist (line backlink-lines)
             (insert (apply #'format "\n| | %s | %s |" line)))
-        (when backlink-lines ; only print closing hline when there's something to close
           (insert "\n|---|"))))
     (org-table-align)))