BUG #14693: create materialized view forces btrim

The following bug has been logged on the website:

Bug reference: 14693
Logged by: Ian Boardman
Email address: isb0459(at)gmail(dot)com
PostgreSQL version: 9.4.9
Operating system: Fedora 23
Description:

I am trying to create a materialized view. I have a working SQL query that
uses this expression: coalesce(trim(foo), bar). When I use that in the
definition for create materialized view, Postgres force replaces the trim()
call into a btrim() and breaks the query result. In my specific case, all
the values become empty instead of yielding either the trimmed "foo" or the
"bar" fields if trimmed "foo" is empty. Is there a way to make Postgres use
the function trim as I require?