diff options
Diffstat (limited to 'src/backend/utils/adt/ruleutils.c')
| -rw-r--r-- | src/backend/utils/adt/ruleutils.c | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 039f897331c..63b85566822 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -2561,6 +2561,12 @@ decompile_column_index_array(Datum column_index_array, Oid relId, * the one specified by the second parameter. This is sufficient for * partial indexes, column default expressions, etc. We also support * Var-free expressions, for which the OID can be InvalidOid. + * + * We expect this function to work, or throw a reasonably clean error, + * for any node tree that can appear in a catalog pg_node_tree column. + * Query trees, such as those appearing in pg_rewrite.ev_action, are + * not supported. Nor are expressions in more than one relation, which + * can appear in places like pg_rewrite.ev_qual. * ---------- */ Datum @@ -2622,11 +2628,13 @@ static text * pg_get_expr_worker(text *expr, Oid relid, const char *relname, int prettyFlags) { Node *node; + Node *tst; + Relids relids; List *context; char *exprstr; char *str; - /* Convert input TEXT object to C string */ + /* Convert input pg_node_tree (really TEXT) object to C string */ exprstr = text_to_cstring(expr); /* Convert expression to node tree */ @@ -2634,6 +2642,40 @@ pg_get_expr_worker(text *expr, Oid relid, const char *relname, int prettyFlags) pfree(exprstr); + /* + * Throw error if the input is a querytree rather than an expression tree. + * While we could support queries here, there seems no very good reason + * to. In most such catalog columns, we'll see a List of Query nodes, or + * even nested Lists, so drill down to a non-List node before checking. + */ + tst = node; + while (tst && IsA(tst, List)) + tst = linitial((List *) tst); + if (tst && IsA(tst, Query)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("input is a query, not an expression"))); + + /* + * Throw error if the expression contains Vars we won't be able to + * deparse. + */ + relids = pull_varnos(NULL, node); + if (OidIsValid(relid)) + { + if (!bms_is_subset(relids, bms_make_singleton(1))) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("expression contains variables of more than one relation"))); + } + else + { + if (!bms_is_empty(relids)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("expression contains variables"))); + } + /* Prepare deparse context if needed */ if (OidIsValid(relid)) context = deparse_context_for(relname, relid); |