cmd.exe returns incorrect exit code

Test case ["&& operator should work"](https://github.com/kimmobrunfeldt/spawn-default-shell/blob/dd4e15b4aa5026b2f1f49166c59eaf50705a128b/test/test-basic.js#L24-L31) is failing because cmd.exe doesn't return the exit code as expected.

This is what happens with cmd.exe /c:

It works in a cmd.exe session:

I don't know yet how to fix this issue. If anyone has ideas, please help.

Start with test/test-basic.js lines 24-31 and reproduce the “&& operator should work” case on Windows. Investigate how cmd.exe /c reports the command's exit code compared with an interactive cmd.exe session. Done means the existing test passes with the expected exit code.

Written by the indexing model from the issue text.