In can_coerce_type, verify that a possible type-coercion function

actually returns the type it is named for.

diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c
index f37082a..35312ea 100644 (file)
--- a/src/backend/parser/parse_coerce.c
+++ b/src/backend/parser/parse_coerce.c
@@ -8,13 +8,13 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v 2.36 2000/03/16 06:35:07 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v 2.37 2000/03/19 00:15:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
-
+#include "catalog/pg_proc.h"
 #include "optimizer/clauses.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_expr.h"
@@ -126,6 +126,12 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
 
                result = transformExpr(pstate, (Node *) n, EXPR_COLUMN_FIRST);
 
+               /* safety check that we got the right thing */
+               if (exprType(result) != targetTypeId)
+                       elog(ERROR, "coerce_type: conversion function %s produced %s",
+                                typeTypeName(targetType), 
+                                typeidTypeName(exprType(result)));
+
                /*
                 * If the input is a constant, apply the type conversion function
                 * now instead of delaying to runtime.  (We could, of course,
@@ -163,6 +169,7 @@ can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids)
 {
        int                     i;
        HeapTuple       ftup;
+       Form_pg_proc pform;
        Oid                     oid_array[FUNC_MAX_ARGS];
 
        /* run through argument list... */
@@ -221,9 +228,10 @@ can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids)
                                                                   0);
                if (!HeapTupleIsValid(ftup))
                        return false;
-               /*
-                * should also check the function return type just to be safe...
-                */
+               /* Make sure the function's result type is as expected, too */
+               pform = (Form_pg_proc) GETSTRUCT(ftup);
+               if (pform->prorettype != targetTypeId)
+                       return false;
        }
 
        return true;