Thread: patch to disallow zero length paths in binary (minor bug fix)

Hackers,

Following is a patch to force the path type not to accept a path with
zero points.  This appears to be illegal in the parser, but possible
when sending a well formed packed in binary with zero points.  The old
behavior was this:

ERROR:  floating-point exception
DETAIL:  An invalid floating-point operation was signaled. This probably
means an out-of-range result or an invalid operation, such as division
by zero.

now it should properly display the points out of range error

merlin
eSilo

Index: src/backend/utils/adt/geo_ops.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v
retrieving revision 1.97
diff -r1.97 geo_ops.c
1459c1459
<   if (npts < 0 || npts >= (int32) ((INT_MAX - offsetof(PATH, p[0]))
/ sizeof(Point)))
---
>   if (npts <= 0 || npts >= (int32) ((INT_MAX - offsetof(PATH, p[0])) / sizeof(Point)))

"Merlin Moncure" <mmoncure@gmail.com> writes:
> Following is a patch to force the path type not to accept a path with
> zero points.  This appears to be illegal in the parser, but possible
> when sending a well formed packed in binary with zero points.

Hmm, looks like poly_recv has the same mistake.

Ideally I think it'd be a good idea if these types did allow zero
elements, but that would clearly be a feature extension more than a bug
fix, since the implications aren't entirely obvious.  I concur with
disallowing the case for existing branches.  Will go apply.

            regards, tom lane