Fix new GIST build code to work under CLOBBER_CACHE_ALWAYS.

Can't say if this fixes *all* cases, but at least we get through
the "point" regression test now, which hyrax's last run did not.

Report: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=hyrax&dt=2020-09-19%2021%3A27%3A23

diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 230625cf1e2c680e05801708340b164e0c885d43..5ecc4c87d11940545f77db1cc2025b9a6d3a12b1 100644 (file)
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -408,6 +408,7 @@ gist_indexsortbuild(GISTBuildState *state)
     * replaced with the real root page at the end.
     */
    page = palloc0(BLCKSZ);
+   RelationOpenSmgr(state->indexrel);
    smgrextend(state->indexrel->rd_smgr, MAIN_FORKNUM, GIST_ROOT_BLKNO,
               page, true);
    state->pages_allocated++;