Don't crash if cursor_to_xmlschema is used on a non-data-returning Portal.
cursor_to_xmlschema() assumed that any Portal must have a tupDesc,
which is not so. Add a defensive check.
It's plausible that this mistake occurred because of the rather
poorly chosen name of the lookup function SPI_cursor_find(),
which in such cases is returning something that isn't very much
like a cursor. Add some documentation to try to forestall future
errors of the same ilk.
Report and patch by Boyu Yang (docs changes by me). Back-patch
to all supported branches.
Discussion: https://postgr.es/m/dd343010-c637-434c-a8cb-418f53bda3b8.yangboyu.yby@alibaba-inc.com
Branch
------
REL_13_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/e6e50ada07bbbbea2a68597d0bf7f795b0dc1269
Modified Files
--------------
doc/src/sgml/spi.sgml | 13 +++++++++++++
src/backend/utils/adt/xml.c | 4 ++++
2 files changed, 17 insertions(+)
