pub unsafe extern "C" fn git_email_create_from_diff( out: *mut git_buf, diff: *mut git_diff, patch_idx: usize, patch_count: usize, commit_id: *const git_oid, summary: *const c_char, body: *const c_char, author: *const git_signature, given_opts: *const git_email_create_options) -> c_int