Because WINENV is limited (32767 bytes), and HOSTENV can be much larger, a whitelisting approach is used to keep WINENV as small as possible. Currently, only the following envvars are propagated from the host env to WINENV WINEPATH, WINEPWD, WINEHOME, WINETEMP, WINETMP, WINEQT_, WINEVK_, WINEXDG_SESSION_TYPE
Moreover, the NIXENV (env for running wine processes - not applications) on the host system is not produced from WINENV anymore, but the global ENV is propagated to all wine processes and threads.
This might be an alternative approach to MR!5231, MR!6140, bug #56941 and should provide a more deterministic behaviour of wine, because unrelated envvars do have no influence on the env for running windows applications.
Initial tests (winemine, notepad, cmd, etc) seem to run fine, but some envvars might need additional consideration. XVDK_* was mentioned, WINE*, MESA_*, VK_*, QT_*, LIBGL_* are other suspects.
Moreover, this is my first merge request, so your feedback is highly appreciated.