Release/5.5.1-alpha0

** See https://github.com/EDCD/EDMarketConnector/releases/tag/Release%2F5.7.1-alpha1 instead for a 64-bit test version.**

• We now test against, and package with, Python 3.10.8 64-bit. In part this change to 64-bit is because py2exe, the program we employ to create windows executables, is no longer warranting that their 32-bit versions will continue to work (they no longer run 32-bit tests).

  Another advantage to switching to 64-bit is in case any data-hungry plugins attempt to use around/more than 2GiB of RAM at once. With 64-bit Python as the basis the only limit will be your system RAM and 'page file' space.

• ctypes code (for Windows API calls) has been updated where necessary to work with 64-bit Python.

• The ctypes code to invoke a "choose a folder" dialog for Settings > Output tab > File location > Browser has been removed in favour of always using tkinter.filedialog().

  • This was tested as still working under Windows 10 21H2 (Build 19044.2311), even when forcing a UTF-8 locale to not be selected and selecting a folder containing Unicode characters.

  • The Windows UTF-8 code page has been available since Windows 10 Build 1903, and even that version is no longer supported, so any supported version of Windows 10 shouldn't have a problem with this.

  • The last Windows 8.1 build is still supported until 'Jan 10, 2023' and might have an issue with this. But as that 'end of life' date is very much in sight we don't plan to hold back the change just for that OS.

Those statements about (un)supported OS versions not withstanding, please do test this version and that specific functionality on any and all Windows systems which ran EDMarketConnector 5.5.0 without issues.

NB: If you make use of any third-party plugins that utilise extra modules which themselves use native libraries then you might find that plugin no longer works. The plugin author will likely need to make a new release which contains the 64-bit versions of any libraries, rather than the 32-bit version they would have been supplying up until now. Please report the issue to them, not us.

Plugin Developers

As noted above, if any third-party plugin is shipped with extra python modules that include native libraries then you will need to switch to shipping the 64-bit versions of those libraries.

There shouldn't be any other impact on plugins, as no API interfaces have changed. Although if your own code utilises any ctypes calls you might also find that it needs updating or replacing.

The key thing to look out for there is where the naive way to call a ctypes-mediated Windows API function defaults the return type to int. On 32-bit Python this is OK if the actual return type is meant to be a pointer, as the two types are of the same size and that pointer will continue to work if passed through to another ctypes function. However on 64-bit python the size of int is still 32 bits, but the pointers are 64 bits. Thus any returned pointer gets erroneously cast and truncated to 32 bits unless you properly declare the function prototype first.

See https://docs.python.org/3/library/ctypes.html#ctypes.WINFUNCTYPE for how to properly declare a function prototype, including return value.

Due to this move to 64-bit Python being a potentially breaking change for some plugins we will be bumping our major version in the final release, i.e. to 6.0.0. We're holding off on that for these alpha releases in case we need to backout/delay this change, not wanting to have testers on an alpha version that is considered newer than a release 5.6.0 or later 5.x.y version.