Bug 506643

Summary:	Can only select languages supported by plasmashell
Product:	[Applications] systemsettings	Reporter:	tusooa <tusooa>
Component:	kcm_regionandlang	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	hanyoung, kde
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Gentoo Packages
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description tusooa 2025-07-05 16:25:06 UTC

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SUMMARY
In the "region and language" KCM, I can only select a few languages for which the file "plasmashell.mo" exists (reading from the code).
This is problematic because (1) other applications may support more languages than Plasma; (2) a distribution may choose to install only the translation files that the user has enabled; (3) the user might want to use a language for other applications.

STEPS TO REPRODUCE
1. Go to "region and language" KCM, click "Modify" on "Language"
2. Click "Add more..."

OBSERVED RESULT
Only a few languages show up. (I use Gentoo, and only those languages enabled in LINGUAS are installed for plasmashell)

EXPECTED RESULT
All languages should show up. The definition of "all" is up to debate, for example, it can be all languages supported by glibc, or qt, or all locales available on the current system. Optionally, we can include a filter checkbox called "Only show languages supported by Plasma," where we return to the current behaviour.

SOFTWARE/OS VERSIONS
Windows:
macOS:
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma:
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION
When I have en_CA.utf8 as the system locale, entering this KCM will display `The language "en_CA" is unsupported.` I would recommend changing this wording as well. It can be better phrased as "The language ... is not supported by Plasma, but other applications that do support it will display their UI in this language."

Comment 1 David Edmundson 2025-07-07 13:59:25 UTC

Whilst you are technically correct, the intention is to not show options that don't appear to work.  Making it complex to support broken setups or entirely niche cases would not be a better change.

Comment 2 tusooa 2025-07-07 14:07:40 UTC

(In reply to David Edmundson from comment #1)
> Whilst you are technically correct, the intention is to not show options
> that don't appear to work.  Making it complex to support broken setups or
> entirely niche cases would not be a better change.

Then it should display a message for advanced users on how to make the changes themselves. Looking at the source code, it is written into plasma-localerc.

Comment 3 hanyoung 2025-07-08 13:31:22 UTC

> Then it should display a message for advanced users on how to make the changes themselves.

I mean, the usual Linux locale setting method also works. In fact, distributions for advanced users like ArchLinux deliberately disabled Plasma's auto locale generation  feature, in favor of the old-fashioned manual one.