[iOS][globalization][NativeAOT] CultureInfo.CurrentCulture does not include region code

[tipa]

Description

CultureInfo.CurrentCulture.Name returns just "en", even if a non-English region is set in the iOS settings (such as "Germany")

Reproduction Steps

• Specify iOS settings as can be seen in the screenshot below
• create new iOS app (dotnet new ios) and set PublishAot=true in csproj
• get iOS device ID using xcrun xctrace list devices
• run dotnet publish -t:Run -p:_DeviceName=DEVICE_ID

Example project: ios_test.zip

Expected behavior

CultureInfo.CurrentCulture.Name returns "en-DE"

Actual behavior

CultureInfo.CurrentCulture.Name returns "en"

Regression?

No response

Known Workarounds

I can construct my own, custom CultureInfo:
new CultureInfo(CultureInfo.CurrentCulture.TwoLetterISOLanguageName + "-" + NSLocale.CurrentLocale.RegionCode)

Configuration

.NET 9.0.4
iOS 18.4.1
iPhone SE

Other information

Perhaps related to #113614

CultureInfo.CurrentCulture.Name returns "en-DE" as expected when running in Debug mode (or in Release mode without using PublishAot=true) and also in a net9.0-macos app using these settings (Debug and Release mode):

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-globalization
See info in area-owners.md if you want to be subscribed.

[dotnet-policy-service]

Tagging subscribers to 'os-ios': @vitek-karas, @kotlarmilos, @ivanpovazan, @steveisok, @akoeplinger
See info in area-owners.md if you want to be subscribed.

[tarekgh]

@matouskozak please triage. Thanks!

[matouskozak]

@ivanpovazan do you have any suggestions on why would NativeAOT behave differently than Mono in release? Based on my understanding the Globalization code is not Mono specific but here it seems like NativeAOT is using the "old" version (before #111612) where only language code is returned.

[ivanpovazan]

hello @tipa, I tried to reproduce your issue with NativeAOT on iOS device but I wasn't able to.

Configuration

• device: iPhone Xr
• iOS version: 18.1.1
• dotnet info:

.NET SDK:
 Version:           9.0.203
 Commit:            dc7acfa194
 Workload version:  9.0.200-manifests.78a0f7ac
 MSBuild version:   17.13.20+a4ef1e90f

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  15.4
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/9.0.203/

.NET workloads installed:
 [ios]
   Installation Source: SDK 9.0.200
   Manifest Version:    18.4.9288/9.0.100
   Manifest Path:       /usr/local/share/dotnet/sdk-manifests/9.0.100/microsoft.net.sdk.ios/18.4.9288/WorkloadManifest.json
   Install Type:        FileBased

Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.4
  Architecture: arm64
  Commit:       f57e6dc747

• build command: dotnet publish -r ios-arm64 -t:Run -bl

Output

• App

• Language/region config

--

Could you run dotnet --info and share it here just to be sure we are using the same version?
Additionally, could you share the binlog of the build when you notice the issue?

[dotnet-policy-service]

This issue has been marked needs-author-action and may be missing some important information.

[tipa]

Thanks for your response @ivanpovazan. I was under the impression that I am on .NET 9.0.4 but I was in fact on 9.0.2 - updating to 9.0.4 seems to have fixed the problem. Sorry for the trouble, I think this can be closed then.