New submission from Eryk Sun <eryk...@gmail.com>:
getenvironment() in Modules/_winapi.c needs to sort variables in the environment block and remove duplicates case insensitively [1]. The sort order used to matter with SetEnvironmentVairableW(). As soon as it reached a name in the environment block that compared greater than the target name, it would insert a new variable. Nowadays, SetEnvironmentVairableW() searches the entire environment block before inserting a new value. Regardless, at the very least, getenvironment() is not well-behaved and not setting the environment in the documented sort order that users, and possibly other programs, expect. Case-insensitive sorting in Windows uses upper case. The variable names in the mapping can be added to a list and sorted with a key function that's based on LCMapStringEx() [2], with the flag LCMAP_UPPERCASE. Loop over the sorted list to create the environment block. Remove duplicates by skipping a name that compares equal to the previously stored name according to CompareStringOrdinal() [3]. _winapi.LCMapStringEx(src, flags=LCMAP_UPPERCASE, locale=LOCALE_NAME_INVARIANT) could also be used in ntpath.normcase(), which would resolve bpo-42658. --- [1] https://docs.microsoft.com/en-us/windows/win32/procthread/changing-environment-variables [2] https://docs.microsoft.com/en-us/windows/win32/api/winnls/nf-winnls-lcmapstringex [3] https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-comparestringordinal ---------- components: Extension Modules, Windows messages: 390038 nosy: eryksun, paul.moore, steve.dower, tim.golden, zach.ware priority: normal severity: normal stage: needs patch status: open title: [Windows] correctly sort and remove duplicates in _winapi getenvironment() type: behavior versions: Python 3.10, Python 3.8, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue43702> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
