Re: pg should ignore u+200b zero width space

Heikki Linnakangas <hlinnaka@iki.fi> writes:
> On 03/11/2020 16:52, Tom Lane wrote:
>> Perhaps it'd be all right to confine the change in behavior to
>> just modifying the error text in cases where we were going to
>> throw an error anyway.  But I think this is much harder than
>> it sounds to do in a valid, safe way.

> Yeah, my thinking was to just add a hint when you're throwing a syntax 
> error anyway. Something simple like check if client_encoding is utf8 and 
> there is a U+200b in the query string, and add the hint if so. It 
> doesn't need to catch all cases, and rare false positives are OK too.

TBH, that's exactly the kind of under-baked solution I *don't* want.

For starters, &zwsp is hardly the only problem here; even more common
is  , which exists in most encodings not only UTF8.  And once we
had that, there'd no doubt be pressure to ignore BOMs.  And so on.

Also I don't really want us throwing such errors when the funny space is
inside a literal or comment; chasing false positives like that will cost
users way more time than they could save when the hint is on-point.

            regards, tom lane