BUG #6495: mis-sorting on string field consisting of space-padded numbers

The following bug has been logged on the website:

Bug reference: 6495
Logged by: Lou Duchez
Email address: lou(at)paprikash(dot)com
PostgreSQL version: 9.1.2
Operating system: Fedora 16, CentOS 5
Description:

Download the following file and feed it into psql:

http://www.paprikash.com/lou/missorttest.sql

Then run the command:

select * from missorttest order by hiercode;

Each "hiercode" entry contains concatenations of numbers, where each number
is left-padded to take exactly four characters. PostgreSQL is sorting as if
the padding were on the right. As a result, " 2 10" is coming before "
2 2", even though a literal sorting of the string should put " 2 2"
first (because chr 32 comes before chr 49).

More info: this error does not occur on the Windows build of PostgreSQL.
Also, I compile my own versions of PostgreSQL on Fedora and CentOS, taking
all the defaults.