Function svn_error_quick_wrap 

pub unsafe extern "C" fn svn_error_quick_wrap(
    child: *mut svn_error_t,
    new_msg: *const c_char,
) -> *mut svn_error_t

If @a child is SVN_NO_ERROR, return SVN_NO_ERROR. Else, prepend a new error to the error chain of @a child. The new error uses @a new_msg as error message but all other error attributes (such as the error code) are copied from @a child.