On 2014-01-25 17:15:01 -0500, Bruce Momjian wrote:
> On Sat, Jan 25, 2014 at 04:56:37PM -0500, Tom Lane wrote:
> > Bruce Momjian <bruce@momjian.us> writes:
> > > On Sat, Jan 25, 2014 at 10:40:28PM +0100, Andres Freund wrote:
> > >> I think this style of pinhole copy editing is pretty pointless. There's
> > >> dozen checks just like this around. If somebody wants to change the rules
> > >> or improve comment it takes more than picking a random one.
> >
> > > OK, change made.
> >
> > FWIW, I don't find that an improvement either. As Andres says, this
> > is just applying the same rule that's used in many other places, ie
> > return null if the requested attnum is off the end of the tuple.
>
> OK, I can revert it, but I don't see any other cases of the string
> 'return NULL if' in the executor code. What the code really is doing is
> "Assume NULL so return true if". The code was never returning NULL, it
> was assuming the attribute was NULL and returning true. Am I missing
> something?
The friggin function in which you whacked around the comment is called
"slot_attisnull()". Referring to the functions meaning in a comment
above an early return isn't a novel thing.
Just search for attnum > tupleDesc->natts to find lots of similar chunks
of code, several of them even in the same file.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services