Re: [rfc] unicode escapes for extended strings

Sam Mason <sam@samason.me.uk> writes:
> On Fri, Apr 17, 2009 at 07:01:47PM +0200, Martijn van Oosterhout wrote:
>> On Fri, Apr 17, 2009 at 07:07:31PM +0300, Marko Kreen wrote:
>>> Btw, is there any good reason why we don't reject \000, \x00
>>> in text strings?
>> 
>> Why forbid nulls in text strings?

> As far as I know, PG assumes, like most C code, that strings don't
> contain embedded NUL characters.

Yeah; we should reject them because nothing will behave very sensibly
with them, eg

regression=# select E'abc\000xyz';?column? 
----------abc
(1 row)

The point has come up before, and I kinda thought we *had* changed the
lexer to reject \000.  I see we haven't though.  Curiously, this
does fail:

regression=# select U&'abc\0000xyz';        
ERROR:  invalid byte sequence for encoding "SQL_ASCII": 0x00
HINT:  This error can also happen if the byte sequence does not match the encoding expected by the server, which is
controlledby "client_encoding".
 

though that's not quite the message I'd have expected to see.
        regards, tom lane