Copy a Param's location field when replacing it with a Const.

tglsfdc · tglsfdc · commit be850f1822e4 · 2021-07-14T14:15:12.000-04:00
This allows Param substitution to produce just the same result as writing a constant value literally would have done. While it hardly matters so far as the current core code is concerned, extensions might take more interest in node location fields. Julien Rouhaud Discussion: https://postgr.es/m/20170311220932.GJ15188@nol.local
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
@@ -2329,20 +2329,23 @@ eval_const_expressions_mutator(Node *node,
 							int16		typLen;
 							bool		typByVal;
 							Datum		pval;
+							Const	   *con;
 
 							get_typlenbyval(param->paramtype,
 											&typLen, &typByVal);
 							if (prm->isnull || typByVal)
 								pval = prm->value;
 							else
 								pval = datumCopy(prm->value, typByVal, typLen);
-							return (Node *) makeConst(param->paramtype,
-													  param->paramtypmod,
-													  param->paramcollid,
-													  (int) typLen,
-													  pval,
-													  prm->isnull,
-													  typByVal);
+							con = makeConst(param->paramtype,
+											param->paramtypmod,
+											param->paramcollid,
+											(int) typLen,
+											pval,
+											prm->isnull,
+											typByVal);
+							con->location = param->location;
+							return (Node *) con;
 						}
 					}
 				}
