[16.0][FIX] attachment_zipped_download: create temporary file to stream

[len-foss]

Despite accurately getting the size from the BytesIO object, Werkzeug doesn't stream its content.
This updates the code to use Odoo's http.Stream class.

Fixes #406

[pedrobaeza]

Tested and working

[github-actions]

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[len-foss]

Is there any reason not to merge this?

[petrus-v]

Code looks good but I've the feeling it's a shame here, we have a new class to manage stream and we are not using it...

_create_temp_zip() return a BytesIO the getvalue() return the raw bytes which is then transform again as a bytesIO by the htpp.Stream class. In a large zip file this could be a lot of memory.

The title told us that it create a temporary file to stream but I don't think it's the case with this change. I've the feeling it would be probably better to do that, change a bit _create_temp_zip to write a temporary file and use Stream with type="path"

As far i understand this mainly avoid to use a deprecated method that I won't be opposed, the improvement can come later !

[len-foss]

The history is lost because I force-pushed the branch (a long time ago so it was pruned); the first version used fo = tempfile.NamedTemporaryFile(); fo.write(out_file.getvalue()) and passed fo as the stream argument.
What bothered me is that in any case we have a call to getvalue.
If there's a better way we can go for it, I just didn't find one.

[aleuffre]

Code review

[pedrobaeza]

/ocabot merge patch

[OCA-git-bot]

On my way to merge this fine PR!
Prepared branch 16.0-ocabot-merge-pr-430-by-pedrobaeza-bump-patch, awaiting test results.

[OCA-git-bot]

Congratulations, your PR was merged at dafab10. Thanks a lot for contributing to OCA. ❤️