Fix Window Resizing Edge Case

[daniellerozenblit]

This PR fixes the bug addressed in #3239.

I have implemented the fix proposed and have validated that the issue no longer occurs.

dd if=/dev/zero of=testFile  bs=1024M  count=1

./zstd --long=31 -1 --single-thread --no-content-size -f ~/testFile
~/testFile :  0.00%   ( 1.000 GiB =>   32.0 KiB, /home/drozenblit/testFile.zst) 

./zstd -l -v ~/testFile.zst
Window Size: 1.000 GiB (1073741824 B)

[Cyan4973]

Would it be possible to add an associated test in playTests.sh ?

[terrelln]

I'd recommend adding a test to cli-tests compression tests, should be a bit easier than in playTests.sh.

https://github.com/facebook/zstd/tree/dev/tests/cli-tests/compression
https://github.com/facebook/zstd/tree/dev/tests/cli-tests/README.md

[Cyan4973]

One way to silence stderr could be 2> /dev/null (redirects stderr to /dev/null)

[Cyan4973]

minor : I'm wondering what happens if this file is not provided, or if it is replaced by the *.ignore suffix variant.
This could be a more explicit way to express that stderr output is not significant.
cc @terrelln .

[daniellerozenblit]

Using the .ignore suffix seems to work! I can switch to that, I like that it is a bit more explicit than redirection.