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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-10-11 21:28:05 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-10-11 21:28:05 +0000 |
| commit | ef3ff3eee48d88ce35b87409c0d96a12f75f044b (patch) | |
| tree | 1c4da6a080cf1a739c4662874b7ee4adf5fa07f2 | |
| parent | a948f7c62ce478af2de8b39366cc10166486a85d (diff) | |
| download | postgresql-ef3ff3eee48d88ce35b87409c0d96a12f75f044b.tar.gz | |
Ensure that the result of evaluating a function during constant-expression
simplification gets detoasted before it is incorporated into a Const node.
Otherwise, if an immutable function were to return a TOAST pointer (an
unlikely case, but it can be made to happen), we would end up with a plan
that depends on the continued existence of the out-of-line toast datum.
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 207eeb7bf2..1a06839e73 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.223.2.3 2007/05/01 18:54:01 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.223.2.4 2007/10/11 21:28:05 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -3040,9 +3040,20 @@ evaluate_expr(Expr *expr, Oid result_type) /* Get back to outer memory context */ MemoryContextSwitchTo(oldcontext); - /* Must copy result out of sub-context used by expression eval */ + /* + * Must copy result out of sub-context used by expression eval. + * + * Also, if it's varlena, forcibly detoast it. This protects us against + * storing TOAST pointers into plans that might outlive the referenced + * data. + */ if (!const_is_null) - const_val = datumCopy(const_val, resultTypByVal, resultTypLen); + { + if (resultTypLen == -1) + const_val = PointerGetDatum(PG_DETOAST_DATUM_COPY(const_val)); + else + const_val = datumCopy(const_val, resultTypByVal, resultTypLen); + } /* Release all the junk we just created */ FreeExecutorState(estate); |