gh-69714: Make calendar module fully tested

Lib/calendar.py

@@ -585,8 +585,6 @@ def __enter__(self):
         _locale.setlocale(_locale.LC_TIME, self.locale)
 
     def __exit__(self, *args):
-        if self.oldlocale is None:
-            return
         _locale.setlocale(_locale.LC_TIME, self.oldlocale)
 
 
@@ -690,7 +688,7 @@ def timegm(tuple):
     return seconds
 
 
-def main(args):
+def main(args=None):
     import argparse
     parser = argparse.ArgumentParser()
     textgroup = parser.add_argument_group('text only arguments')
@@ -747,7 +745,7 @@ def main(args):
         help="month number (1-12, text only)"
     )
 
-    options = parser.parse_args(args[1:])
+    options = parser.parse_args(args)
 
     if options.locale and not options.encoding:
         parser.error("if --locale is specified --encoding is required")
@@ -756,6 +754,9 @@ def main(args):
     locale = options.locale, options.encoding
 
     if options.type == "html":
+        if options.month:
+            parser.error("incorrect number of arguments")
+            sys.exit(1)
         if options.locale:
             cal = LocaleHTMLCalendar(locale=locale)
         else:
@@ -767,11 +768,8 @@ def main(args):
         write = sys.stdout.buffer.write
         if options.year is None:
             write(cal.formatyearpage(datetime.date.today().year, **optdict))
-        elif options.month is None:
-            write(cal.formatyearpage(options.year, **optdict))
         else:
-            parser.error("incorrect number of arguments")
-            sys.exit(1)
+            write(cal.formatyearpage(options.year, **optdict))
     else:
         if options.locale:
             cal = LocaleTextCalendar(locale=locale)
@@ -795,4 +793,4 @@ def main(args):
 
 
 if __name__ == "__main__":
-    main(sys.argv)
+    main()