diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/parser/parse_coerce.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c index e7278374544..6661a3d8a1d 100644 --- a/src/backend/parser/parse_coerce.c +++ b/src/backend/parser/parse_coerce.c @@ -79,10 +79,24 @@ coerce_to_target_type(ParseState *pstate, Node *expr, Oid exprtype, int location) { Node *result; + Node *origexpr; if (!can_coerce_type(1, &exprtype, &targettype, ccontext)) return NULL; + /* + * If the input has a CollateExpr at the top, strip it off, perform the + * coercion, and put a new one back on. This is annoying since it + * duplicates logic in coerce_type, but if we don't do this then it's too + * hard to tell whether coerce_type actually changed anything, and we + * *must* know that to avoid possibly calling hide_coercion_node on + * something that wasn't generated by coerce_type. Note that if there are + * multiple stacked CollateExprs, we just discard all but the topmost. + */ + origexpr = expr; + while (expr && IsA(expr, CollateExpr)) + expr = (Node *) ((CollateExpr *) expr)->arg; + result = coerce_type(pstate, expr, exprtype, targettype, targettypmod, ccontext, cformat, location); @@ -98,6 +112,18 @@ coerce_to_target_type(ParseState *pstate, Node *expr, Oid exprtype, (cformat != COERCE_IMPLICIT_CAST), (result != expr && !IsA(result, Const))); + if (expr != origexpr) + { + /* Reinstall top CollateExpr */ + CollateExpr *coll = (CollateExpr *) origexpr; + CollateExpr *newcoll = makeNode(CollateExpr); + + newcoll->arg = (Expr *) result; + newcoll->collOid = coll->collOid; + newcoll->location = coll->location; + result = (Node *) newcoll; + } + return result; } @@ -318,7 +344,7 @@ coerce_type(ParseState *pstate, Node *node, * If we have a COLLATE clause, we have to push the coercion * underneath the COLLATE. This is really ugly, but there is little * choice because the above hacks on Consts and Params wouldn't happen - * otherwise. + * otherwise. This kluge has consequences in coerce_to_target_type. */ CollateExpr *coll = (CollateExpr *) node; CollateExpr *newcoll = makeNode(CollateExpr); |