[apple] Failure in System.Globalization.Tests.StringNormalizationTests.Normalize tests

[BrzVlad]

This happens in test suites: System.Globalization.Extensions.iOS.Tests and System.Globalization.Extensions.Tests
It impacts all apple lanes. Other configs not affected. Fails on maccatalyst_x64, maccatalyst_arm64, iossimulator_x64, ios-arm64.

Sample failure:

[FAIL] System.Globalization.Tests.StringNormalizationTests.Normalize(value: "ÄÇ", normalizationForm: FormC, expected: "ÄÇ")
[04:39:50.5756830] Assert.Equal() Failure: Values differ
[04:39:50.5756940] Expected: 2
[04:39:50.5757040] Actual:   0
[04:39:50.5757150] 2024-12-15 01:39:50.661 System.Globalization.Extensions.iOS.Tests[94400:124587059]    at System.Globalization.Tests.StringNormalizationTests.Normalize(String value, NormalizationForm normalizationForm, String expected)
[04:39:50.5757500]    at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
[04:39:50.5757630] 2024-12-15 01:39:50.661 System.Globalization.Extensions.iOS.Tests[94400:124587059]    at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
[04:39:50.5822700] 2024-12-15 01:39:50.668 System.Globalization.Extensions.iOS.Tests[94400:124587059] 

Regressed recently. Most likely caused by a5af0ab

[BrzVlad]

@tarekgh Any idea what is going on and how the fix should look like ?

[tarekgh]

@BrzVlad could you please disable the failing test against an active issue till we investigate?

CC @matouskozak if he can help till, I am back?

I have some suspicion GetNormalizedLength is not returning the correct result on iOS (or similar platforms)

runtime/src/libraries/System.Runtime/tests/System.Globalization.Extensions.Tests/Normalization/StringNormalizationTests.cs

Line 92 in 3aa1ec5

Assert.Equal(expected.Length, value.AsSpan().GetNormalizedLength());

runtime/src/libraries/System.Runtime/tests/System.Globalization.Extensions.Tests/Normalization/StringNormalizationTests.cs

Line 113 in 3aa1ec5

Assert.Equal(expected.Length, value.AsSpan().GetNormalizedLength(normalizationForm));

[tarekgh]

I think I understand what the problem is.

The following line expect returning the right length:

runtime/src/libraries/System.Private.CoreLib/src/System/Globalization/Normalization.Icu.cs

Line 181 in 3aa1ec5

realLen = Interop.Globalization.NormalizeStringNative(normalizationForm, pInput, source.Length, null, 0);

while the iOS implementation doesn't allow empty buffers while it should do (as other platform implementations do).

runtime/src/native/libs/System.Globalization.Native/pal_normalization.m

Line 73 in 3aa1ec5

if (normalizedString == NULL || normalizedString.length == 0)

@BrzVlad I'll try to fix this at first chance. I would appreciate it if you could disable the test against active issue till, I fix it. Sorry for the inconvenience,

[tarekgh]

I opened the PR #110723. I didn't test it because I don't have the environment setup, but I believe it will fix the issue.

[BrzVlad]

@tarekgh Doesn't seem like the PR is fixing the tests. Will disable the test until you have more time to investigate. #110725.

cc @ivanpovazan