On Linux, wchar_t values are mapped to their UTF-8 counterparts; however, that does not have to be the case as the standard allows any arbitrary representation to be used, and this is the case for Solaris.

In Oracle Solaris, the internal form of wchar_t is specific to a locale; in the Unicode locales, wchar_t has the UTF-32 Unicode encoding form, and other locales have different representations [1].

This is an issue because Python expects wchar_t to correspond with Unicode, which on Oracle Solaris with non-UTF locale results either in errors (values are outside the Unicode range) or in output with different symbols.

Unicode locales work as expected, but they are not an acceptable workaround for some Oracle Solaris users that cannot use Unicode encoding for various reasons.


Because of that, we fixed it a few months ago with a patch to `PyUnicode_FromWideChar`, which handles conversion to unicode (attached in PR). It was tested over the last half a year, and we didn't see any related issues since.

Is something like this acceptable or should it be fixed on a different place/in a different way? All comments are appreciated.

[1] https://docs.oracle.com/cd/E36784_01/html/E39536/gmwkm.html

I forgot to mention: this affects Oracle Solaris. I tested this on SmartOS, and I cannot reproduce it there as it seems that they are using Unicode representation for all locales. Based on the documentation, this might also affect other systems as well (e.g. HP UIX specifically says: 'These values may not be compatible with values obtained by specifying other locales that are supported'), but it's hard to tell without testing that.

This one liner breaks with ValueError: character U+30000069 is not in range [U+0000; U+10ffff] if the issue is present:
python3.7 -c 'import datetime; import locale; locale.setlocale(locale.LC_ALL,"es_ES.ISO8859-1"); datetime.date(2001, 1, 3).strftime("%a")'

New changeset 9032cf5cb1e33c0349089cfb0f6bf11ed3c30e86 by Jakub Kulík in branch 'master':
bpo-43667: Fix broken Unicode encoding in non-UTF locales on Solaris (GH-25096)
https://github.com/python/cpython/commit/9032cf5cb1e33c0349089cfb0f6bf11ed3c30e86

New changeset d3cc68900dc99966007112f884779895daefc7db by Jakub Kulík in branch '3.9':
[3.9] bpo-43667: Fix broken Unicode encoding in non-UTF locales on Solaris (GH-25096) (GH-25847)
https://github.com/python/cpython/commit/d3cc68900dc99966007112f884779895daefc7db

Backport to 3.8 may be more complicated. It's up to you to decide if you want to backport it or not. I merged your 3.9 backport, it looks very close to the change made in the main branch.

Do you want to attempt to backport the fix to 3.8, or can this issue be closed?

Sorry for delayed response.

Considering that we are not delivering or using 3.8 in any way and this issue doesn't seem to impact anybody else, we can omit the backport to 3.8. I will prepare another PR with a news fragment, and after that, this can be considered solved and closed.

I close the issue, but you can still reference the bpo issue number for your PR with the changelog (NEWS) entry.

New changeset 164a4f46d1606e21d82babc010e397a9116e6730 by Jakub Kulík in branch 'main':
bpo-43667: Add news fragment for Solaris changes (GH-26405)
https://github.com/python/cpython/commit/164a4f46d1606e21d82babc010e397a9116e6730

New changeset 0574b0686d76e6f9199f800b5f32bd56eaff3c77 by Miss Islington (bot) in branch '3.10':
bpo-43667: Add news fragment for Solaris changes (GH-26405) (GH-26409)
https://github.com/python/cpython/commit/0574b0686d76e6f9199f800b5f32bd56eaff3c77

New changeset 427232f9d221d54870fa3e89bd1dac55cf42243f by Miss Islington (bot) in branch '3.9':
bpo-43667: Add news fragment for Solaris changes (GH-26405) (GH-26410)
https://github.com/python/cpython/commit/427232f9d221d54870fa3e89bd1dac55cf42243f

I merged your PR and backported it to add a NEWS entry, thanks.

New changeset f87d2038fadd9c067d50fb2f1d7c2f37b9f3893a by Miss Islington (bot) in branch '3.10':
bpo-43667: Add news fragment for Solaris changes (GH-26405) (GH-26498)
https://github.com/python/cpython/commit/f87d2038fadd9c067d50fb2f1d7c2f37b9f3893a