Check after errors of SPI_execute() in xml.c
SPI gets used to build a list of relation OIDs for XML object
generation, and one code path building a list uses SPI_execute() without
looking at errors it produces. So fix that.
Author: Mark Dilger
Reviewed-by: Michael Paquier, Pavel Stehule
Discussion: https://postgr.es/m/
17d30445-4862-7917-170f-
84328dcd292d@gmail.com