Fix write corruption caused by writing an unintended NUL byte

[segevfiner]

Closes spyder-ide/pywinpty#210

[codecov-commenter]

Codecov Report

Merging #16 (7d0ec8c) into main (3b08c65) will decrease coverage by 0.02%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #16      +/-   ##
==========================================
- Coverage   74.50%   74.48%   -0.03%     
==========================================
  Files           8        8              
  Lines        1208     1207       -1     
==========================================
- Hits          900      899       -1     
  Misses        308      308              

Flag	Coverage Δ
unittests	74.48% <100.00%> (-0.03%)	:arrow_down:

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Impacted Files	Coverage Δ
src/pty/base.rs	71.84% <100.00%> (-0.09%)	:arrow_down:

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[andfoy]

Thanks for your contribution @segevfiner, I have only one question: When writing the PSTR into the file, the NUL character is no longer necessary? Also, is this problem also happening when reading bytes?

[segevfiner]

Yeah. Just the bytes without a NUL byte, as this is a "file" write and you are passing the size of the byte array/string to be written. Same as in a normal file, if you write a NUL byte into it, the NUL byte itself will also appear in the file rather than just the text. I haven't noticed a problem on read, as in, I don't see any extra NUL bytes there.

[andfoy]

Thanks for the fix! I'll publish a new release