Alignment handling broken?

[danielocfb]

I tried upgrading to version 1.1 and it seems as if handling of alignment is broken.

use std::env;
use std::fs::read as read_file;
use std::fs::File;
use std::io::Write as _;
use std::path::Path;

use zip::write::SimpleFileOptions;
use zip::CompressionMethod;
use zip::ZipArchive;
use zip::ZipWriter;

fn main() {
    let page_size = 4096;
    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let dst_dir = Path::new(&crate_dir);
    let dst_file = dst_dir.join("test.zip");

    {
        let dst_file = File::options()
            .create(true)
            .truncate(true)
            .read(false)
            .write(true)
            .open(&dst_file)
            .unwrap();

        let options = SimpleFileOptions::default()
            .compression_method(CompressionMethod::Stored)
            .with_alignment(page_size.try_into().unwrap());
        let mut zip = ZipWriter::new(dst_file);
        let contents = read_file("/usr/bin/sleep").unwrap();
        let () = zip.start_file("sleep", options).unwrap();
        let _count = zip.write(&contents).unwrap();
    }

    {
        let dst_file = File::open(dst_file).unwrap();
        let mut zip = ZipArchive::new(dst_file).unwrap();
        let file = zip.by_index(0).unwrap();
        assert_eq!(file.name(), "sleep");
        assert_eq!(file.data_start(), page_size);
    }
}

fails with:

thread 'main' panicked at src/main.rs:41:9:
assertion `left == right` failed
  left: 4092
 right: 4096
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Similar code on 0.6.4 works fine:

use std::env;
use std::fs::read as read_file;
use std::fs::File;
use std::io::Write as _;
use std::path::Path;

use zip::write::FileOptions;
use zip::CompressionMethod;
use zip::ZipArchive;
use zip::ZipWriter;

fn main() {
    let page_size = 4096;
    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let dst_dir = Path::new(&crate_dir);
    let dst_file = dst_dir.join("test.zip");

    {
        let dst_file = File::options()
            .create(true)
            .truncate(true)
            .read(false)
            .write(true)
            .open(&dst_file)
            .unwrap();

        let options = FileOptions::default().compression_method(CompressionMethod::Stored);
        let mut zip = ZipWriter::new(dst_file);
        let contents = read_file("/usr/bin/sleep").unwrap();
        let _align = zip
            .start_file_aligned(
                "sleep",
                options,
                page_size.try_into().unwrap(),
            )
            .unwrap();
        let _count = zip.write(&contents).unwrap();
    }

    {
        let dst_file = File::open(dst_file).unwrap();
        let mut zip = ZipArchive::new(dst_file).unwrap();
        let file = zip.by_index(0).unwrap();
        assert_eq!(file.name(), "sleep");
        assert_eq!(file.data_start(), page_size);
    }
}

Am I misunderstanding what is being aligned?