Ex: The 4.4 upgrader checks `customCSSURL` and sets `disable_core_css`
depending on whether the value is empty. Since the addTrailingSlash was
converting empty to '/', this caused bad upgrades.
case 'setting-url-abs':
case 'setting-url-rel':
$type = (strstr($type, 'abs')) ? 'absolute' : 'relative';
- $value = CRM_Utils_File::addTrailingSlash($this->getSettings()->get($name));
+ $value = $this->getSettings()->get($name);
+ if ($value) {
+ $value = CRM_Utils_File::addTrailingSlash($value);
+ }
$this->cache[$k] = Civi::paths()->getUrl($value, $type);
return $this->cache[$k];