Function svn_io_dir_file_copy 

pub unsafe extern "C" fn svn_io_dir_file_copy(
    src_path: *const c_char,
    dest_path: *const c_char,
    file: *const c_char,
    pool: *mut apr_pool_t,
) -> *mut svn_error_t

Copy the file whose basename (or relative path) is @a file within directory @a src_path to the same basename (or relative path) within directory @a dest_path. Overwrite the destination file if it already exists. The destination directory (including any directory components in @a name) must already exist. Set the destination file’s permissions to match those of the source. Use @a pool for memory allocations.