fix Windows nightly build uploads

[AntonioBL]

This is another tentative at fixing Windows nightly uploading when using Appveyor MSVC 2019 image.

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[Spire42]

I just looked into this.

The SETLOCAL and ENDLOCAL commands are there because msvc_build.bat should not be polluting all developers' environments with mysterious generically-named variables just because AppVeyor happens to need one of them. (Also, we need to make sure that command extensions are enabled, and SETLOCAL is the command that does that.)

Anyway, to address the problem at hand:

Appveyor is apparently relying on BUILD_FOLDER having been set by msvc_build.bat, which is not a good idea at all. (OTOH, it's not using INSTALL_FOLDER, which I guess we can be thankful for.)

To fix this, I don't think we should be reverting to the old behavior of polluting the environment.

The real fix would be to provide a better and clearly documented optional mechanism for msvc_build.bat to communicate any required information back to its caller. (My suggestion is to add an optional command-line parameter that explicitly specifies the target build folder, which would actually turn the communication the other way around.)

In the meantime, I think we can implement a quick fix without touching msvc_build.bat that takes advantage of the fact that msvc_build.bat ends with the current working directory set to the build folder.

To do this in your current PR, first undo the changes to msvc_build.bat, then add this line to the end of build\appveyor\build_script.bat (after the two calls to msvc_build.bat):

FOR %%I in (.) DO SET BUILD_FOLDER=%%~nxI

I don't have access to an AppVeyor environment to test this, so could you please test and see if this works?

[AntonioBL]

Thank you for your comment.
I tried, but unfortunately the folder is reset to parent folder (MuseScore folder) after the execution of
msvc_build.bat (both when running locally, and also on Appveyor, see for example here: https://ci.appveyor.com/project/AntonioBL/musescore/builds/32282810/job/w473c4kdhn3k97wc#L3462 ).
But then I thought that this (deploy and upload) script just need to correctly run on Appveyor only, so I tried to use env variables defined by Appveyor (as they are already used by the script), and I found that the architecture value is defined in "PLATFORM" variable.
It works, for both x86 (see https://ci.appveyor.com/project/AntonioBL/musescore/builds/32283051/job/8nk9vkckp5pseco5#L3464 ) and x64 (see https://ci.appveyor.com/project/AntonioBL/musescore/builds/32283051/job/cyd4l5p6u1q8kgh4#L3439 ).
I updated the PR.
Thank you for your help.

[Spire42]

Sorry that my suggestion didn't end up being useful. I'm glad that you were able to come up with something better!

[Jojo-Schmitz]

Indeed fixed, MuseScoreNightly-2020-04-21-1415-master-333752a-x86_64.7z is there now