lts/doc/guides/maintaining-zlib.md
# Maintaining zlib
This copy of zlib comes from the Chromium team's zlib fork which incorporated
performance improvements not currently available in standard zlib.
## Updating zlib
Update zlib:
```bash
git clone https://chromium.googlesource.com/chromium/src/third_party/zlib
cp deps/zlib/zlib.gyp deps/zlib/win32/zlib.def deps
rm -rf deps/zlib zlib/.git
mv zlib deps/
mv deps/zlib.gyp deps/zlib/
mkdir deps/zlib/win32
mv deps/zlib.def deps/zlib/win32
sed -i -- 's_^#include "chromeconf.h"_//#include "chromeconf.h"_' deps/zlib/zconf.h
```
Check that Node.js still builds and tests.
It may be necessary to update deps/zlib/zlib.gyp if any significant changes have
occurred upstream.
## Committing zlib
Add zlib: `git add --all deps/zlib`
Commit the changes with a message like
```text
deps: update zlib to upstream d7f3ca9
Updated as described in doc/guides/maintaining-zlib.md.
```