[3.13] gh-112346: Always set OS byte to 255, simpler gzip.compress function. (GH-120486) by miss-islington · Pull Request #120563 · python/cpython

@rhpvorderman @miss-islington

…ction. (pythonGH-120486)

This matches the output behavior in 3.10 and earlier; the optimization in 3.11 allowed the zlib library's "os" value to be filled in instead in the circumstance when mtime was 0.  this keeps things consistent.
(cherry picked from commit 08d09cf)

Co-authored-by: Ruben Vorderman <r.h.p.vorderman@lumc.nl>

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Jun 15, 2024