Обсуждение: Aren't lseg_eq and lseg_ne broken?

By chance I just noticed that lseg equality is coded as

Datum
lseg_eq(PG_FUNCTION_ARGS)
{   LSEG       *l1 = PG_GETARG_LSEG_P(0);   LSEG       *l2 = PG_GETARG_LSEG_P(1);
   PG_RETURN_BOOL(FPeq(l1->p[0].x, l2->p[0].x) &&                  FPeq(l1->p[1].y, l2->p[1].y) &&
FPeq(l1->p[0].x,l2->p[0].x) &&                  FPeq(l1->p[1].y, l2->p[1].y));
 
}

Surely this should be
   PG_RETURN_BOOL(FPeq(l1->p[0].x, l2->p[0].x) &&                  FPeq(l1->p[0].y, l2->p[0].y) &&
FPeq(l1->p[1].x,l2->p[1].x) &&                  FPeq(l1->p[1].y, l2->p[1].y));
 

since I don't think I like this result:

regression=# select '[(0, 0), (1, 1)]'::lseg = '[(0, 42), (2, 1)]'::lseg;?column?
----------t
(1 row)

lseg_ne has the identical bug.

Checking the CVS archives, I see that this error dates back to the
original Berkeley code, so I'm a bit hesitant to just change it.
Is there any possibility that it really should work this way?
        regards, tom lane

Tom Lane wrote:
> By chance I just noticed that lseg equality is coded as
> 
> Datum
> lseg_eq(PG_FUNCTION_ARGS)
> {
>     LSEG       *l1 = PG_GETARG_LSEG_P(0);
>     LSEG       *l2 = PG_GETARG_LSEG_P(1);
> 
>     PG_RETURN_BOOL(FPeq(l1->p[0].x, l2->p[0].x) &&
>                    FPeq(l1->p[1].y, l2->p[1].y) &&
>                    FPeq(l1->p[0].x, l2->p[0].x) &&
>                    FPeq(l1->p[1].y, l2->p[1].y));
> }
> 
> Surely this should be
> 
>     PG_RETURN_BOOL(FPeq(l1->p[0].x, l2->p[0].x) &&
>                    FPeq(l1->p[0].y, l2->p[0].y) &&
>                    FPeq(l1->p[1].x, l2->p[1].x) &&
>                    FPeq(l1->p[1].y, l2->p[1].y));

Yep, there could be no possible reason to double-test something like the
original code does.  It must be wrong.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073