[postgis-devel] NULL from Z() and M() ?

[strk at refractions.net]

I think this issue raised many other times now, anyway, here
it is again:

	since X(), Y(), Z() and M() return NULL
	when input is NOT a point, shouldn't they
	return NULL also when corresponding 
	coordinate is not available (for Z and M
	only) ? Current behaviour is returning 0.


	I suggest we make these return NULL instead:

		Z(POINT2D) 
		Z(POINT3DM) 
		M(POINT2D) 
		M(POINT2DZ) 

What was the CON again - if anyone recall it ?

--strk;