BUG #12458: Comparison with CHAR is inconsistent between string types

The following bug has been logged on the website:

Bug reference:      12458
Logged by:          Thomas Neumann
Email address:      tneumann@users.sourceforge.net
PostgreSQL version: 9.4.0
Operating system:   Linux 3.16
Description:

The following two queries return different results:

select 'A'::char(1)='A '::text;
select 'A'::char(1)='A '::varchar(10);

I would expect both queries to return "true", and this is also suggested by
the documentation (section 8.3.), but the text comparison returns false.