pgsql: Check for stack overflow in transformSetOperationTree(). - Mailing list pgsql-committers

From Tom Lane
Subject pgsql: Check for stack overflow in transformSetOperationTree().
Date
Msg-id E1TXiKn-0003tu-Qd@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Check for stack overflow in transformSetOperationTree().

Since transformSetOperationTree() recurses, it can be driven to stack
overflow with enough UNION/INTERSECT/EXCEPT clauses in a query.  Add a
check to ensure it fails cleanly instead of crashing.  Per report from
Matthew Gerber (though it's not clear whether this is the only thing
going wrong for him).

Historical note: I think the reasoning behind not putting a check here in
the beginning was that the check in transformExpr() ought to be sufficient
to guard the whole parser.  However, because transformSetOperationTree()
recurses all the way to the bottom of the set-operation tree before doing
any analysis of the statement's expressions, that check doesn't save it.

Branch
------
REL8_4_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/78542e37b8e1b25f329e4baac618da39ee8f911b

Modified Files
--------------
src/backend/parser/analyze.c |    4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)


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