Maintenance: updated vendored minizip code to the version distributed with zlib v1.3.1

[jayaddison]

Updates the vendored copy of minizip within libxlsxwriter to the version distributed with version 1.3.1 of zlib.

The diff here should match with the relevant changes between v1.3 and v1.3.1 of zlib ( madler/zlib@v1.3...v1.3.1 ), with the exception of 1dfd55b that is a cherry-pick already applied locally (#427) from madler/zlib@73331a6 (an upstream fix).

Test results:

• make test
  • unit tests: 430 passed, 0 failed, 0 skipped.
  • functional tests: 759 passed, 0 failed, 0 skipped.
• make test_valgrind
  • completed successfully with exit code zero.

(this is a follow-up to issue #419; I'd been awaiting an updated version of zlib and don't plan to track any further releases against that issue number)

[jmcnamara]

Thanks.

The ioapi.h and zip.h files also need to be copied into include/xlsxwriter/third_party. After that you may need to change some // style comments to /**/ to fix some warnings. There may be other minor warnings as well. You may see some of the required changes in the diff against the existing code.

[jayaddison]

Thanks @jmcnamara - whereabouts do those warnings appear? (to make sure I'm resolving them correctly after the file copy)

[jmcnamara]

whereabouts do those warnings appear? (to make sure I'm resolving them correctly after the file copy)

@jayaddison I can't reproduce the warning anymore. Copy the files without changes and if the CI is okay I will merge it.

[jmcnamara]

Merged. Thanks.

[jayaddison]

You're welcome - thanks @jmcnamara.