Re: Backslash characters in PLPGSQL

"Garrett Murphy" <gmurphy@lawlogix.com> writes:
> We recently upgraded from 8.3 to 8.4 and are noticing a change in
> behavior that we can't seem to associate with a particular server
> setting.

I think you're seeing the effects of this 8.4 patch:
http://archives.postgresql.org/pgsql-committers/2009-04/msg00216.php
in particular:

* In standard_conforming_strings mode, backslash as the last character of a non-E string literal is now correctly taken
asan ordinary character; formerly it was misinterpreted as escaping the ending quote.  (Since the string also had to
passthrough the core scanner, this invariably led to syntax errors.)
 

However, as I wrote there, I was under the impression that this fix
didn't break any cases that actually worked usefully before 8.4.
I tried your example and as far as I can tell, 8.3.x fails on
test_function2(), giving "unterminated string" with or without
standard_conforming_strings set.  But 8.4 accepts it, if you have
standard_conforming_strings set.  I wonder whether your actual
function has yet another improperly terminated string on another
line, thereby allowing the 8.3 plpgsql scanner to get back into
sync.  But it's not obvious why that wouldn't lead to visible
misbehavior, or why 8.4 would not like it.
        regards, tom lane