Re: Tightening isspace() tests where behavior should match SQL parser

I wrote:
> Heikki Linnakangas <hlinnaka@iki.fi> writes:
>> +1 for back-patching. If I understand correctly, it would change the 
>> behavior when you pass a string with non-ASCII leading or trailing 
>> whitespace characters to those functions. I suppose that can happen, but 
>> it's only pure luck if the current code happens to work in that case. 

> Well, it'd work properly for e.g. no-break space in LATINn.

Actually, it's dubious that treating no-break space as whitespace is
correct at all in these use-cases.  The core scanner would think it's
an identifier character, so it's not impossible that somebody would
consider it cute to write &nbsp; as part of a SQL identifier.  If
the core scanner accepts that, so must these functions.

Hence, applied and back-patched.

			regards, tom lane