[ruby/zlib] [Bug #18358] Fix crash in zlib when in progress

    When Zlib::Inflate#inflate or Zlib::Deflate#deflate is called
    recursively inside the block, a crash can occur because of an
    use-after-free bug.

    https://github.com/ruby/zlib/commit/50fb8a0338
    ---
     ext/zlib/zlib.c        | 117 ++++++++++++++++++++++++++++++++-----------------
     test/zlib/test_zlib.rb |  10 ++++-
     2 files changed, 85 insertions(+), 42 deletions(-)

    [ruby/zlib] Synchronize access to zstream to prevent segfault in
     multithreaded use

    I'm not sure whether this handles all multithreaded use cases,
    but this handles the example that crashes almost immediately
    and does 10,000,000 total deflates using 100 separate threads.

    To prevent the tests from taking forever, the committed test
    for this uses only 10,000 deflates across 10 separate threads,
    which still causes a segfault in the previous implementation
    almost immediately.

    Fixes [Bug #17803]

    https://github.com/ruby/zlib/commit/4b1023b3f2
    ---
     ext/zlib/zlib.c        | 33 ++++++++++++++++++++++++++-
     test/zlib/test_zlib.rb | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++
     2 files changed, 93 insertions(+), 1 deletion(-)

	[ruby/zlib] Resume zstream if available [Bug #10961]

	---
	 ext/zlib/zlib.c | 6 ++++++
	 1 file changed, 6 insertions(+)

https://github.com/ruby/zlib/commit/5af77c1ee8

https://github.com/ruby/zlib/commit/3e98e4cac3

Before this change, it was not possible to write out zero for the
timestamp part of a Gzip file's header, as calling GzipWriter#mtime with
zero was ignored.

Judging from the docs for `GzipWriter#mtime=`, it should be possible to
indicate that no timestamp is available by calling the method with zero.

https://github.com/ruby/zlib/commit/310be39cac

Ruby 2.7 deprecates taint and it no longer has an effect.
The lack of taint support should not cause a problem in
previous Ruby versions.

https://github.com/ruby/zlib/commit/21711ed0ce

https://github.com/ruby/zlib/commit/00ead8cb2c

https://github.com/ruby/zlib/commit/8f43b264cd