Re: jsonb, unicode escapes and escaped backslashes

On 2015-01-29 16:33:36 -0500, Andrew Dunstan wrote:
> 
> On 01/29/2015 12:10 PM, Robert Haas wrote:
> >On Wed, Jan 28, 2015 at 12:48 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >>The cause of this bug is commit 0ad1a816320a2b539a51628e2a0b1e83ff096b1d,
> >>which I'm inclined to think we need to simply revert, not render even
> >>more squirrely.
> >Yes, that commit looks broken.  If you convert from text to JSON you
> >should get a JSON string equivalent to the text you started out with.
> >That commit departs from that in favor of allowing \uXXXX sequences in
> >the text being converted to turn into a single character (or perhaps
> >an encoding error) after a text->json->text roundtrip.  Maybe I
> >haven't had enough caffeine today, but I can't see how that can
> >possibly be a good idea.

> I'm coming down more and more on the side of Tom's suggestion just to ban
> \u0000 in jsonb. I think that would let us have some fairly simple and
> consistent rules. I'm not too worried that we'll be disallowing input that
> we've previously allowed. We've done that often in the past, although less
> often in point releases. I certainly don't want to wait a full release cycle
> to fix this if possible.

I think waiting a full cycle would be likely to make things much worse,
given 9.4's current age.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services