Thread: pgsql: Modify hash_search() API to prevent future occurrences of the

Log Message:
-----------
Modify hash_search() API to prevent future occurrences of the error
spotted by Qingqing Zhou.  The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places.  If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL.  But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.

Modified Files:
--------------
    pgsql/contrib/dblink:
        dblink.c (r1.41 -> r1.42)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/dblink/dblink.c.diff?r1=1.41&r2=1.42)
    pgsql/contrib/tablefunc:
        tablefunc.c (r1.34 -> r1.35)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/tablefunc/tablefunc.c.diff?r1=1.34&r2=1.35)
    pgsql/src/backend/access/transam:
        xlogutils.c (r1.36 -> r1.37)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlogutils.c.diff?r1=1.36&r2=1.37)
    pgsql/src/backend/commands:
        prepare.c (r1.37 -> r1.38)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/prepare.c.diff?r1=1.37&r2=1.38)
    pgsql/src/backend/executor:
        execGrouping.c (r1.14 -> r1.15)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execGrouping.c.diff?r1=1.14&r2=1.15)
    pgsql/src/backend/nodes:
        tidbitmap.c (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/tidbitmap.c.diff?r1=1.3&r2=1.4)
    pgsql/src/backend/postmaster:
        pgstat.c (r1.94 -> r1.95)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/pgstat.c.diff?r1=1.94&r2=1.95)
    pgsql/src/backend/storage/buffer:
        buf_table.c (r1.40 -> r1.41)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/buf_table.c.diff?r1=1.40&r2=1.41)
        localbuf.c (r1.66 -> r1.67)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/localbuf.c.diff?r1=1.66&r2=1.67)
    pgsql/src/backend/storage/freespace:
        freespace.c (r1.44 -> r1.45)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/freespace/freespace.c.diff?r1=1.44&r2=1.45)
    pgsql/src/backend/storage/ipc:
        shmem.c (r1.83 -> r1.84)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/shmem.c.diff?r1=1.83&r2=1.84)
    pgsql/src/backend/storage/lmgr:
        lock.c (r1.152 -> r1.153)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/lock.c.diff?r1=1.152&r2=1.153)
    pgsql/src/backend/storage/smgr:
        md.c (r1.114 -> r1.115)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/smgr/md.c.diff?r1=1.114&r2=1.115)
        smgr.c (r1.86 -> r1.87)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/smgr/smgr.c.diff?r1=1.86&r2=1.87)
    pgsql/src/backend/utils/adt:
        ri_triggers.c (r1.77 -> r1.78)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ri_triggers.c.diff?r1=1.77&r2=1.78)
    pgsql/src/backend/utils/cache:
        relcache.c (r1.224 -> r1.225)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relcache.c.diff?r1=1.224&r2=1.225)
        typcache.c (r1.13 -> r1.14)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/typcache.c.diff?r1=1.13&r2=1.14)
    pgsql/src/backend/utils/fmgr:
        fmgr.c (r1.94 -> r1.95)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/fmgr.c.diff?r1=1.94&r2=1.95)
    pgsql/src/backend/utils/hash:
        dynahash.c (r1.60 -> r1.61)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/hash/dynahash.c.diff?r1=1.60&r2=1.61)
    pgsql/src/backend/utils/mmgr:
        portalmem.c (r1.79 -> r1.80)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mmgr/portalmem.c.diff?r1=1.79&r2=1.80)
    pgsql/src/include/utils:
        hsearch.h (r1.35 -> r1.36)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/hsearch.h.diff?r1=1.35&r2=1.36)
    pgsql/src/pl/plpgsql/src:
        pl_comp.c (r1.89 -> r1.90)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_comp.c.diff?r1=1.89&r2=1.90)
    pgsql/src/timezone:
        pgtz.c (r1.31 -> r1.32)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/timezone/pgtz.c.diff?r1=1.31&r2=1.32)