fix for #368

ChangeLog

@@ -1,3 +1,10 @@
+2024-02-06 Richard Frith-Macdonald <[email protected]>
+
+	* Source/NSLocale.m: (+canonicalLocaleIdentifierFromString:)
+	Fix for #368 ... standardise hyphen to underscore then check for
+	presence of two underscores and delete the script identifier between
+	them, as suggested by the existing comments.  Avoids the exception.
+
 2024-02-02 Richard Frith-Macdonald <[email protected]>
 
 	Source/NSString.m: Return empty string of correct class when loading

Source/NSLocale.m

@@ -36,6 +36,7 @@
 #import "Foundation/NSNumberFormatter.h"
 #import "Foundation/NSUserDefaults.h"
 #import "Foundation/NSString.h"
+#import "GNUstepBase/NSMutableString+GNUstepBase.h"
 #import "GNUstepBase/GSLock.h"
 
 #if	defined(HAVE_UNICODE_ULOC_H)
@@ -272,18 +273,36 @@ + (NSString *) canonicalLocaleIdentifierFromString: (NSString *) string
   if (result == nil)
     result = string;
 
-  // Strip script info from locale
+  /* Strip script info (if present) from locale.
+   * We try to cope with zh-Hant_TW or zh_Hant-TW
+   */
+  mStr = nil;
   range = [result rangeOfString: @"-"];
+  if (range.length > 0)
+    {
+      mStr = [NSMutableString stringWithString: result];
+      [mStr replaceString: @"-" withString: @"_"];
+      result = mStr;
+    }
+  range = [result rangeOfString: @"_"];
   if (range.location != NSNotFound)
     {
       NSUInteger start = range.location;
-      NSUInteger length;
-      range = [result rangeOfString: @"_"];
-      length = range.location - start;
-
-      mStr = [NSMutableString stringWithString: result];
-      [mStr deleteCharactersInRange: NSMakeRange (start, length)];
+
+      range = [result rangeOfString: @"_" options: NSBackwardsSearch];
+      if (range.location != start)
+	{
+	  NSUInteger length = range.location - start;
 
+	  if (nil == mStr)
+	    {
+	      mStr = [NSMutableString stringWithString: result];
+	    }
+	  [mStr deleteCharactersInRange: NSMakeRange(start, length)];
+	}
+    }
+  if (mStr)
+    {
       result = [NSString stringWithString: mStr];
     }