pgsql: Fix 'negative bitmapset member' error

Fix 'negative bitmapset member' error

When removing a useless join, we'd remove PHVs that are not used at join
partner rels or above the join.  A PHV that references the join's relid
in ph_eval_at is logically "above" the join and thus should not be
removed.  We have the following check for that:

    !bms_is_member(ojrelid, phinfo->ph_eval_at)

However, in the case of SJE removing a useless inner join, 'ojrelid' is
set to -1, which would trigger the "negative bitmapset member not
allowed" error in bms_is_member().

Fix it by skipping examining ojrelid for inner joins in this check.

Reported-by: Zuming Jiang
Bug: #18260
Discussion: https://postgr.es/m/18260-1b6a0c4ae311b837%40postgresql.org
Author: Richard Guo
Reviewed-by: Andrei Lepikhov

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/fe093994db4dc5dcc239f8839b094c0b75de00cf

Modified Files
--------------
src/backend/optimizer/plan/analyzejoins.c |  2 +-
src/test/regress/expected/join.out        | 20 ++++++++++++++++++++
src/test/regress/sql/join.sql             |  8 ++++++++
3 files changed, 29 insertions(+), 1 deletion(-)