fix: disallow empty tags

src/endpoints/api_v1_tags.c

@@ -70,6 +70,16 @@ api_v1_tags_POST(struct mg_connection *nc, struct http_message *hm, endpoint_arg
         return;
     }
 
+    if(strlen(json_tag->valuestring) == 0)
+    {
+        LOGGER_DEBUG("tag is empty\n");
+        cJSON_Delete(json);
+
+        static const char content[] = "tag is empty";
+        endpoint_response_text(response, 400, content, STRLEN(content));
+        return;
+    }
+
     if(tag_save(0, json_tag->valuestring))
     {
         LOGGER_DEBUG("tag could not be saved\n");