Hello,<br /><br />I have been working with the PostGIS developers, and I'm implementing a facility to use 'callback'
functionsto process cells in a raster image.<br /><br />I have implemented this behind the scenes as a C function that
callsa provided sql regprocedure with OidFunctionCall*. I have been reading the docs, and it states that "Note that
neitherarguments nor result are allowed to be NULL."<br /><br />In this use case, there are legitimate reasons to
returnNULL from a 'callback' function -- is there an alternative method that I should use, instead of
OidFunctionCall*?<br/><br />Thanks,<br />David<br />
