Re: allowing multiple PQclear() calls

2012-12-11 12:45 keltezéssel, Simon Riggs írta:
> On 11 December 2012 10:39, Marko Kreen <markokr(at)gmail(dot)com> wrote:
>> On Tue, Dec 11, 2012 at 6:59 AM, Josh Kupershmidt <schmiddy(at)gmail(dot)com> wrote:
>>> Would it be crazy to add an "already_freed" flag to the pg_result
>>> struct which PQclear() would set, or some equivalent safety mechanism,
>>> to avoid this hassle for users?
>> Such mechanism already exist - you just need to set
>> your PGresult pointer to NULL after each PQclear().
> So why doesn't PQclear() do that?

Because then PQclear() would need a ** not a *. Do you want its
interface changed for 9.3 and break compatibility with previous versions?
Same can be said for e.g. PQfinish(). Calling it again crashes your client,
as I have recently discovered when I added atexit() functions that
does "if (conn) PQfinish(conn);" and the normal flow didn't do conn = NULL;
after it was done.

>
> Maintaining a pointer to something that no longer exists seems strange.
>
> Under what conditions would anybody want the old pointer value after PQclear() ?

>

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