TW-1795: Calendar underline on Day padding

- Thanks to Renato Alves.

ChangeLog

@@ -12,6 +12,8 @@
           (thanks to Sebastien Badia).
 - TW-1792 The info command uses '0' to reference dependencies on non-
           pending tasks.
+- TW-1795 Calendar underline on Day padding
+          (thanks to Renato Alves).
 - Added 'juhannus' as a synonym for 'midsommarafton'
           (thanks to Lynoure Braakman).
 - Deprecated the 'DUETODAY' virtual tag, which is a synonym for the 'TODAY'

src/commands/CmdCalendar.cpp

@@ -516,7 +516,11 @@ std::string CmdCalendar::renderMonths (
       int woy = temp.weekOfYear (weekStart);
 
       if (context.config.getBoolean ("displayweeknumber"))
-        view.set (row, (8 * mpl), woy, color_weeknumber);
+        view.set (row,
+                  (8 * mpl),
+                  // Make sure the week number is always 4 columns, space-padded.
+                  format ((woy < 10 ? "   {1}" : "  {1}"), woy),
+                  color_weeknumber);
 
       // Calculate column id.
       int thisCol = dow +                       // 0 = Sunday