Fix Issue 22998 - Update to zlib 1.2.12

[ibara]

Hello --

I've updated the copy of zlib in Phobos.

Here's a reprinting of the big-ticket items from the zlib.net homepage:
Version 1.2.12 has these key improvements over 1.2.11:

• Fix a deflate bug when using the Z_FIXED strategy that can result in out-of-bound accesses.
• Fix a deflate bug when the window is full in deflate_stored().
• Speed up CRC-32 computations by a factor of 1.5 to 3.
• Use the hardware CRC-32 instruction on ARMv8 processors.
• Speed up crc32_combine() with powers of x tables.
• Add crc32_combine_gen() and crc32_combine_op() for fast combines.
  Due to the bug fixes, any installations of 1.2.11 should be replaced with 1.2.12.

Also maintains the fix from here:
ibara@1b6cf80

Everything appears OK on my OpenBSD/amd64 machine. But perhaps more testing from others is in order.

[ibara]

(Force-pushed to quell a buildkite/phobos error complaining about the style of a comment...)
And also to maybe to get the bot to recognize this PR.

[ibuclaw]

🙈

[ibuclaw]

The style checker will always fire for this, so better revert to the previous range style.

[ibara]

OK, will do.

[ibara]

Done.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	22998	normal	Update to zlib 1.2.12

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + phobos#8428"

[dkorpel]

Please add "Fix Issue 22998" to the commit title so the bot links it to the bugzilla issue.

[lulcat]

Hi. I was just looking at the zlib 1.2.11 to 1.2.12 this very moment and saw your post from these days. Great! This was due to wanting to update zstd to current. I believe that finally there has come a natural replacement of the venerable zlib/[gzip]. Anyway, thanks for this, and wondering @ibara , if this is something you might join in or have plans about etc? I will test the 1.2.12, I suppose I need to grab the git version?
On a side note, why is the sources of zlib-1.2.11 in etc/c/zlib? I noticed it was mainly the !_DMD macro thing which was the only difference. Does dmd compile with those sources implicitly or something? (I ask because I am uncertain if I locally should drop zstd lib sources potentially in there or so).

[ibara]

Since you pinged me, when you say updating zstd, do you mean the dub package here: https://code.dlang.org/packages/zstd ? If so, it's not my package so I can't tell you when it will be updated.

If you're talking about replacing zlib with zstd in Phobos, then I imagine that would be a bigger change in need of serious discussion (and numbers) to demonstrate that it is a net gain. I am not part of the DLF, just a user and I guess de facto OpenBSD OS maintainer for D, so I doubt a proposal from me would carry much weight without lots of hard numbers. I don't have the time to do that right now.

[ibuclaw]

I'm hearing whispers that 1.2.13 is already upcoming due to a CRC regression that's been fixed in the devel branch. If it isn't happening before the next release, perhaps we should cherry-pick?

[ibuclaw]

@ibara I've just remembered that a changelog entry would be ideal so it gets picked up in the notes for the next release.

[ibara]

I thought the bugzilla tracking and closing would do that for us. But can add a changelog entry as well.

[ibara]

I'm hearing whispers that 1.2.13 is already upcoming due to a CRC regression that's been fixed in the devel branch. If it isn't happening before the next release, perhaps we should cherry-pick?

Good idea.

[lulcat]

Looking at how that bug is worded, cherrypicking might not be uber important (I don't dare say), but had it been literally erronous crc's in current, then yes. Regarding zstd @ibara , yes I mean tthe dub package. I have updated the interface file (using dstep and cleaning up a few bits and bobs there), but I haven't touched the d files the original author had layered on top. It works as before it seems. With that said, in the examples, I get a true vs. false result in 'streaming.d' when doing binary files vs text files. So I assume it's got to do with some string encoding or something although I am not quite getting it why it happens. I'm not tremendous at all with D so. With that said, should someone wish to update it, I can link the dstep file, although it did a fairly good job. Failed to convert two 0ULL to ulong and fixing the version string pretty much as before/zlib.d does. MIght be a digression from this but I include a link anyway. Can remove if preferred to not derail. :)

https://gist.github.com/lulcat/3221f8d30fc8a8aa12faa4024c56edf0

P.S. Forgot to mention, great stuff updating the zlib package, important to have these things up to date.