[library] Add function to delete playlist by id that directly

invalidates the REST API client caches

src/httpd_jsonapi.c

@@ -3581,7 +3581,7 @@ jsonapi_reply_library_playlist_delete(struct httpd_request *hreq)
       return HTTP_BADREQUEST;
     }
 
-  db_pl_delete(pl_id);
+  library_playlist_remove_byid(pl_id);
 
   return HTTP_NOCONTENT;
 }

src/library.c

@@ -742,6 +742,25 @@ library_playlist_remove(char *virtual_path)
   return commands_exec_sync(cmdbase, playlist_remove, NULL, virtual_path);
 }
 
+int
+library_playlist_remove_byid(int pl_id)
+{
+  if (scanning)
+    {
+      DPRINTF(E_INFO, L_LIB, "Scan already running, ignoring request to remove playlist '%d'\n", pl_id);
+      return -1;
+    }
+
+  db_pl_delete(pl_id);
+
+  if (handle_deferred_update_notifications())
+    listener_notify(LISTENER_UPDATE | LISTENER_DATABASE);
+  else
+    listener_notify(LISTENER_UPDATE);
+
+  return 0;
+}
+
 int
 library_queue_save(char *path)
 {

src/library.h

@@ -189,6 +189,9 @@ library_playlist_item_add(const char *vp_playlist, const char *vp_item);
 int
 library_playlist_remove(char *virtual_path);
 
+int
+library_playlist_remove_byid(int plid);
+
 int
 library_queue_save(char *path);