Add support for aliased cultures

Fixes dotnet#3897
0xced · Jan 4, 2021 · d406b08 · d406b08
1 parent 1c88d13
commit d406b08
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diff --git a/src/Tasks.UnitTests/AssignCulture_Tests.cs b/src/Tasks.UnitTests/AssignCulture_Tests.cs
@@ -216,6 +216,56 @@ public void PseudoLocalization(string culture)
             Assert.Equal($"MyResource.{culture}.resx", t.AssignedFiles[0].ItemSpec);
             Assert.Equal("MyResource.resx", t.CultureNeutralAssignedFiles[0].ItemSpec);
         }
+
+        /*
+        * Method:   AliasedCulture
+        *
+        * Test that an aliased culture (e.g. zh-CN or zh-TW) which is _not_ returned by CultureInfo.GetCultures(CultureTypes.AllCultures)
+        * on Unix-based systems is still considered valid.
+        * See also https://github.com/dotnet/msbuild/issues/3897 (Cultures aliased by ICU cannot be used for resource localization on non-Windows environments)
+        */
+        [Theory]
+        [InlineData("zh-CN")]
+        [InlineData("zh-TW")]
+        public void AliasedCulture(string culture)
+        {
+            AssignCulture t = new AssignCulture();
+            t.BuildEngine = new MockEngine();
+            ITaskItem i = new TaskItem($"MyResource.{culture}.resx");
+            t.Files = new ITaskItem[] { i };
+            t.Execute();
+
+            Assert.Single(t.AssignedFiles);
+            Assert.Single(t.CultureNeutralAssignedFiles);
+            Assert.Equal(culture, t.AssignedFiles[0].GetMetadata("Culture"));
+            Assert.Equal($"MyResource.{culture}.resx", t.AssignedFiles[0].ItemSpec);
+            Assert.Equal("MyResource.resx", t.CultureNeutralAssignedFiles[0].ItemSpec);
+        }
+
+        /*
+        * Method:   InvalidCulture
+        *
+        * Test for invalid culture (i.e. throwing an exception when using new CultureInfo())
+        * and unknown culture (i.e. a culture not known by the operating system but which can be created with new CultureInfo())
+        */
+        [Theory]
+        [InlineData("\U0001F4A5")]
+        [InlineData("xx")]
+        public void InvalidCulture(string culture)
+        {
+            AssignCulture t = new AssignCulture();
+            t.BuildEngine = new MockEngine();
+            ITaskItem i = new TaskItem($"MyResource.{culture}.resx");
+            t.Files = new ITaskItem[] { i };
+            t.Execute();
+
+            Assert.Single(t.AssignedFiles);
+            Assert.Single(t.CultureNeutralAssignedFiles);
+            Assert.Equal(String.Empty, t.AssignedFiles[0].GetMetadata("Culture"));
+            Assert.Equal("false", t.AssignedFiles[0].GetMetadata("WithCulture"));
+            Assert.Equal($"MyResource.{culture}.resx", t.AssignedFiles[0].ItemSpec);
+            Assert.Equal($"MyResource.{culture}.resx", t.CultureNeutralAssignedFiles[0].ItemSpec);
+        }
     }
 }
 

diff --git a/src/Tasks/CultureInfoCache.cs b/src/Tasks/CultureInfoCache.cs
@@ -18,10 +18,12 @@ namespace Microsoft.Build.Tasks
     internal static class CultureInfoCache
     {
         private static readonly HashSet<string> ValidCultureNames;
+        private static readonly HashSet<string> InvalidCultureNames;
 
         static CultureInfoCache()
         {
             ValidCultureNames = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+            InvalidCultureNames = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
 
 #if !FEATURE_CULTUREINFO_GETCULTURES
             if (!AssemblyUtilities.CultureInfoHasGetCultures())
@@ -55,7 +57,35 @@ static CultureInfoCache()
         /// <returns>True if the culture is determined to be valid.</returns>
         internal static bool IsValidCultureString(string name)
         {
-            return ValidCultureNames.Contains(name);
+            var isValid = ValidCultureNames.Contains(name);
+            if (isValid)
+                return true;
+
+            var isInvalid = InvalidCultureNames.Contains(name);
+            if (isInvalid)
+                return false;
+
+            CultureInfo culture;
+            try
+            {
+                culture = new CultureInfo(name);
+            }
+            catch (Exception)
+            {
+                InvalidCultureNames.Add(name);
+                return false;
+            }
+
+            // See https://docs.microsoft.com/en-us/dotnet/api/System.Globalization.CultureInfo.LCID#remarks
+            const int LOCALE_CUSTOM_UNSPECIFIED = 0x1000;
+            if (culture.LCID == LOCALE_CUSTOM_UNSPECIFIED)
+            {
+                InvalidCultureNames.Add(name);
+                return false;
+            }
+
+            ValidCultureNames.Add(name);
+            return true;
         }
 
 #if !FEATURE_CULTUREINFO_GETCULTURES