Function svn_relpath_prefix 

pub unsafe extern "C" fn svn_relpath_prefix(
    relpath: *const c_char,
    max_components: c_int,
    result_pool: *mut apr_pool_t,
) -> *const c_char

Return a maximum of @a max_components components of @a relpath. This is an efficient way of calling svn_relpath_dirname() multiple times until only a specific number of components is left.

Allocate the result in @a result_pool (or statically in case of 0)

@since New in 1.9.