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| author | Sverker Eriksson <[email protected]> | 2017-02-28 14:52:08 +0100 |
|---|---|---|
| committer | Sverker Eriksson <[email protected]> | 2017-02-28 14:52:08 +0100 |
| commit | 1b3b07e78580435477eec4d8558e91167b7c03aa (patch) | |
| tree | 6714497790d1adc9fc768e1d9cca5afe87e77bb1 | |
| parent | e6059f94571a6c968c15b9de6b7d63ebd64f9acf (diff) | |
| download | otp-1b3b07e78580435477eec4d8558e91167b7c03aa.tar.gz otp-1b3b07e78580435477eec4d8558e91167b7c03aa.tar.bz2 otp-1b3b07e78580435477eec4d8558e91167b7c03aa.zip | |
zlib: Add warning for option WindowBits values 8 and -8.
| -rw-r--r-- | erts/doc/src/zlib.xml | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml index 138414a880..583d21ad7b 100644 --- a/erts/doc/src/zlib.xml +++ b/erts/doc/src/zlib.xml @@ -315,6 +315,15 @@ list_to_binary([B1,B2])</pre> <c><anno>WindowBits</anno></c> value suppresses the zlib header (and checksum) from the stream. Notice that the zlib source mentions this only as a undocumented feature.</p> + <warning> + <p>Due to a known bug in zlib, <c>WindowsBits</c> values 8 and -8 + do not work as expected. In zlib versions before 1.2.9 values + 8 and -8 are automatically changed to 9 and -9. <em>From zlib version 1.2.9 + value -8 is rejected</em> causing <c>zlib:deflateInit/6</c> to fail + (8 is still changed to 9). It also seem possible that future versions + of zlib may fix this bug and start accepting 8 and -8 as is.</p> + <p>Conclusion: Avoid values 8 and -8 unless you know your zlib version supports them.</p> + </warning> </item> <tag><c><anno>MemLevel</anno></c></tag> <item> |