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.
--
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