Created attachment 124192 [details]
Screenshot of the File -> New dialog

SUMMARY
GUI is mixed between Polish and English, instead of being only English or only Polish. 


STEPS TO REPRODUCE
1. Compile Krita on Polish system.
2. Open File -> New dialog.

OBSERVED RESULT
See the screenshot. There are two buttons, one called "Create" (and for some reason located on the left? Was it always there?...), and the other one called "Anuluj" (Cancel in Polish). 

EXPECTED RESULT
Whole UI has the same language. It can be English, I don't care... but at least one?


ADDITIONAL INFORMATION
Content of my klanguageoverridesrc:
[Language]
krita-4.2.7.1b-x86_64.appimage=@ByteArray(en_US)
krita-4.2.8-beta1-x86_64.appimage=@ByteArray(en_US)
krita-4.2.8-x86_64.appimage=@ByteArray(en_US)

My locale:
LANG=pl_PL.UTF-8
LANGUAGE=pl
LC_CTYPE="pl_PL.UTF-8"
LC_NUMERIC="pl_PL.UTF-8"
LC_TIME="pl_PL.UTF-8"
LC_COLLATE="pl_PL.UTF-8"
LC_MONETARY="pl_PL.UTF-8"
LC_MESSAGES="pl_PL.UTF-8"
LC_PAPER="pl_PL.UTF-8"
LC_NAME="pl_PL.UTF-8"
LC_ADDRESS="pl_PL.UTF-8"
LC_TELEPHONE="pl_PL.UTF-8"
LC_MEASUREMENT="pl_PL.UTF-8"
LC_IDENTIFICATION="pl_PL.UTF-8"
LC_ALL=

Krita -> Help -> Show system information... shows a line:
 Languages: pl
Despite that, most of the GUI is in English. (Appimages by default are in Polish, of course, unless I change them).

Krita -> Settings -> Switch Application Language shows "American English" and no fallback language.

I guess those buttons are created in a different way and Qt somehow is getting the "Anuluj" button from OS in some way... or something...


SOFTWARE/OS VERSIONS
Krita

 Version: 4.3.0-prealpha (git 2d4ae8c)
 Languages: pl
 Hidpi: true

Qt

  Version (compiled): 5.11.1
  Version (loaded): 5.11.1

OS Information

  Build ABI: x86_64-little_endian-lp64
  Build CPU: x86_64
  CPU: x86_64
  Kernel Type: linux
  Kernel Version: 5.3.7-050307-generic
  Pretty Productname: Linux Mint 19.2
  Product Type: linuxmint
  Product Version: 19.2

Hardware Information

  GPU Acceleration: auto
  Memory: 15633 Mb
  Number of Cores: 8
  Swap Location: /tmp

Current Settings

	Current Swap Location: /tmp
	Undo Enabled: 1
	Undo Stack Limit: 30
	Use OpenGL: 1
	Use OpenGL Texture Buffer: 1
	Use AMD Vectorization Workaround: 0
	Canvas State: OPENGL_SUCCESS
	Autosave Interval: 1260
	Use Backup Files: 1
	Number of Backups Kept: 1
	Backup File Suffix: ~
	Backup Location: Same Folder as the File
	Use Win8 Pointer Input: 0
	Use RightMiddleTabletButton Workaround: 0
	Levels of Detail Enabled: 1
	Use Zip64: 0