[jsonapi] expose force metadata rescan via /api/update/meta endpoint

README_JSON_API.md

@@ -723,6 +723,7 @@ curl -X PUT "http://localhost:3689/api/queue/items/2"
 | GET       | [/api/library/count](#get-count-of-tracks-artists-and-albums) | Get count of tracks, artists and albums |
 | GET       | [/api/library/files](#list-local-directories)               | Get list of directories in the local library    |
 | GET       | [/api/update](#trigger-rescan)                              | Trigger a library rescan             |
+| GET       | [/api/update/meta](#trigger-meta-rescan)                    | Trigger a library metadata rescan    |
 
 
 
@@ -1657,6 +1658,25 @@ curl -X GET "http://localhost:3689/api/update"
 }
 ```
 
+### Trigger meta rescan
+
+Trigger a library metadata rescan even if files have not been updated.  Maintenence method.
+
+**Endpoint**
+
+```http
+GET /api/update/meta
+```
+
+**Response**
+
+On success returns the HTTP `204 No Content` success status response code.
+
+**Example**
+
+```shell
+curl -X GET "http://localhost:3689/api/update/meta"
+```
 
 
 ## Search

src/httpd_jsonapi.c

@@ -787,6 +787,14 @@ jsonapi_reply_update(struct httpd_request *hreq)
   return HTTP_NOCONTENT;
 }
 
+static int
+jsonapi_reply_meta_update(struct httpd_request *hreq)
+{
+  library_metarescan();
+  return HTTP_NOCONTENT;
+}
+
+
 /*
  * Endpoint to retrieve information about the spotify integration
  *
@@ -3510,6 +3518,7 @@ static struct httpd_uri_map adm_handlers[] =
     { EVHTTP_REQ_GET,    "^/api/config$",                                jsonapi_reply_config },
     { EVHTTP_REQ_GET,    "^/api/library$",                               jsonapi_reply_library },
     { EVHTTP_REQ_GET,    "^/api/update$",                                jsonapi_reply_update },
+    { EVHTTP_REQ_GET,    "^/api/update/meta$",                           jsonapi_reply_meta_update },
     { EVHTTP_REQ_POST,   "^/api/spotify-login$",                         jsonapi_reply_spotify_login },
     { EVHTTP_REQ_GET,    "^/api/spotify$",                               jsonapi_reply_spotify },
     { EVHTTP_REQ_GET,    "^/api/pairing$",                               jsonapi_reply_pairing_get },