src/java.base/macosx/native/libjava/java_props_macosx.c

*** 111,120 ****
--- 111,126 ----
          }
          break;
      }
  
      if (retVal != NULL) {
+         // convertToPOSIXLocale() does not expect any variant codes, so ignore
+         // '@' and anything following, if present.
+         char* rmAt = strchr(retVal, '@');
+         if (rmAt != NULL) {
+             *rmAt = '\0';
+         }
          return strdup(convertToPOSIXLocale(retVal));
      }
  
      return NULL;
  }