Fix lazy initialization for Minimal Globalization Data

Author: mdh1418

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs

@@ -48,6 +48,26 @@ private static string GetUtcFullDisplayName(string timeZoneId, string standardDi
         }
 #pragma warning restore IDE0060
 
+        private static void GetStandardDisplayName(string timeZoneId, ref string? displayName)
+        {
+            // Determine the culture to use
+            CultureInfo uiCulture = CultureInfo.CurrentUICulture;
+            if (uiCulture.Name.Length == 0)
+                uiCulture = CultureInfo.GetCultureInfo(FallbackCultureName); // ICU doesn't work nicely with InvariantCulture
+
+            GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.Standard, uiCulture.Name, ref displayName);
+        }
+
+        private static void GetDaylightDisplayName(string timeZoneId, ref string? displayName)
+        {
+            // Determine the culture to use
+            CultureInfo uiCulture = CultureInfo.CurrentUICulture;
+            if (uiCulture.Name.Length == 0)
+                uiCulture = CultureInfo.GetCultureInfo(FallbackCultureName); // ICU doesn't work nicely with InvariantCulture
+
+            GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.DaylightSavings, uiCulture.Name, ref displayName);
+        }
+
         // Helper function that retrieves various forms of time zone display names from ICU
         private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalization.TimeZoneDisplayNameType nameType, string uiCulture, ref string? displayName)
         {
@@ -96,8 +116,13 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
         }
 
         // Helper function that builds the value backing the DisplayName field from globalization data.
-        private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan baseUtcOffset, CultureInfo uiCulture, ref string? displayName)
+        private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan baseUtcOffset, ref string? displayName)
         {
+            // Determine the culture to use
+            CultureInfo uiCulture = CultureInfo.CurrentUICulture;
+            if (uiCulture.Name.Length == 0)
+                uiCulture = CultureInfo.GetCultureInfo(FallbackCultureName); // ICU doesn't work nicely with InvariantCulture
+
             // There are a few diffent ways we might show the display name depending on the data.
             // The algorithm used below should avoid duplicating the same words while still achieving the
             // goal of providing a unique, discoverable, and intuitive name.

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs

@@ -6,6 +6,12 @@ namespace System
     public sealed partial class TimeZoneInfo
     {
 #pragma warning disable IDE0060
+        static partial void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan baseUtcOffset, ref string? displayName);
+
+        static partial void GetStandardDisplayName(string timeZoneId, ref string? displayName);
+
+        static partial void GetDaylightDisplayName(string timeZoneId, ref string? displayName);
+
         private static string GetUtcStandardDisplayName()
         {
             // For this target, be consistent with other time zone display names that use an abbreviation.

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs

@@ -231,12 +231,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return displayName;
 
-            // Determine the culture to use
-            CultureInfo uiCulture = CultureInfo.CurrentUICulture;
-            if (uiCulture.Name.Length == 0)
-                uiCulture = CultureInfo.GetCultureInfo(FallbackCultureName); // ICU doesn't work nicely with InvariantCulture
-
-            GetFullValueForDisplayNameField(Id, BaseUtcOffset, uiCulture, ref displayName);
+            GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
 
             return displayName;
         }
@@ -250,11 +245,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return standardDisplayName;
 
-            CultureInfo uiCulture = CultureInfo.CurrentUICulture;
-            if (uiCulture.Name.Length == 0)
-                uiCulture = CultureInfo.GetCultureInfo(FallbackCultureName); // ICU doesn't work nicely with InvariantCulture
-
-            GetDisplayName(Id, Interop.Globalization.TimeZoneDisplayNameType.Standard, uiCulture.Name, ref standardDisplayName);
+            GetStandardDisplayName(Id, ref standardDisplayName);
 
             return standardDisplayName;
         }
@@ -268,12 +259,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return daylightDisplayName;
 
-            // Determine the culture to use
-            CultureInfo uiCulture = CultureInfo.CurrentUICulture;
-            if (uiCulture.Name.Length == 0)
-                uiCulture = CultureInfo.GetCultureInfo(FallbackCultureName); // ICU doesn't work nicely with InvariantCulture
-
-            GetDisplayName(Id, Interop.Globalization.TimeZoneDisplayNameType.DaylightSavings, uiCulture.Name, ref daylightDisplayName);
+            GetDaylightDisplayName(Id, ref daylightDisplayName);
 
             return daylightDisplayName;
         }