get_names_for_var didn't do recursion for unnamed JOIN vars quite right;

tglsfdc · tglsfdc · commit c06b31dc31e5 · 2005-01-13T17:19:10.000Z
got it wrong when the JOIN was in an outer query level.  Per example from
Laurie Burrow.  Also fix same issue in markTargetListOrigin.  I think the
latter is only a latent bug since we currently don't apply markTargetListOrigin
except at the outer level ... but should do it right anyway.
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.128 2004/12/31 22:00:27 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.129 2005/01/13 17:19:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -29,7 +29,8 @@
 #include "utils/typcache.h"
 
 
-static void markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var);
+static void markTargetListOrigin(ParseState *pstate, Resdom *res,
+								 Var *var, int levelsup);
 static Node *transformAssignmentIndirection(ParseState *pstate,
 							   Node *basenode,
 							   const char *targetName,
@@ -174,26 +175,30 @@ markTargetListOrigins(ParseState *pstate, List *targetlist)
 	{
 		TargetEntry *tle = (TargetEntry *) lfirst(l);
 
-		markTargetListOrigin(pstate, tle->resdom, (Var *) tle->expr);
+		markTargetListOrigin(pstate, tle->resdom, (Var *) tle->expr, 0);
 	}
 }
 
 /*
  * markTargetListOrigin()
  *		If 'var' is a Var of a plain relation, mark 'res' with its origin
  *
+ * levelsup is an extra offset to interpret the Var's varlevelsup correctly.
+ *
  * This is split out so it can recurse for join references.  Note that we
  * do not drill down into views, but report the view as the column owner.
  */
 static void
-markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var)
+markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var, int levelsup)
 {
+	int			netlevelsup;
 	RangeTblEntry *rte;
 	AttrNumber	attnum;
 
 	if (var == NULL || !IsA(var, Var))
 		return;
-	rte = GetRTEByRangeTablePosn(pstate, var->varno, var->varlevelsup);
+	netlevelsup = var->varlevelsup + levelsup;
+	rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
 	attnum = var->varattno;
 
 	switch (rte->rtekind)
@@ -223,7 +228,7 @@ markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var)
 
 				Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
 				aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1);
-				markTargetListOrigin(pstate, res, aliasvar);
+				markTargetListOrigin(pstate, res, aliasvar, netlevelsup);
 			}
 			break;
 		case RTE_SPECIAL:
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
@@ -3,7 +3,7 @@
  *				back to source text
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.187 2004/12/13 00:33:06 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.188 2005/01/13 17:19:10 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -182,7 +182,7 @@ static void get_setop_query(Node *setOp, Query *query,
 static Node *get_rule_sortgroupclause(SortClause *srt, List *tlist,
 						 bool force_colno,
 						 deparse_context *context);
-static void get_names_for_var(Var *var, deparse_context *context,
+static void get_names_for_var(Var *var, int levelsup, deparse_context *context,
 				  char **schemaname, char **refname, char **attname);
 static RangeTblEntry *find_rte_by_refname(const char *refname,
 					deparse_context *context);
@@ -1998,7 +1998,7 @@ get_basic_select_query(Query *query, deparse_context *context,
 				char	   *refname;
 				char	   *attname;
 
-				get_names_for_var(var, context,
+				get_names_for_var(var, 0, context,
 								  &schemaname, &refname, &attname);
 				tell_as = (attname == NULL ||
 						   strcmp(attname, colname) != 0);
@@ -2392,6 +2392,10 @@ get_utility_query_def(Query *query, deparse_context *context)
 /*
  * Get the schemaname, refname and attname for a (possibly nonlocal) Var.
  *
+ * In some cases (currently only when recursing into an unnamed join)
+ * the Var's varlevelsup has to be interpreted with respect to a context
+ * above the current one; levelsup indicates the offset.
+ *
  * schemaname is usually returned as NULL.	It will be non-null only if
  * use of the unqualified refname would find the wrong RTE.
  *
@@ -2404,17 +2408,20 @@ get_utility_query_def(Query *query, deparse_context *context)
  * distinguish this case.)
  */
 static void
-get_names_for_var(Var *var, deparse_context *context,
+get_names_for_var(Var *var, int levelsup, deparse_context *context,
 				  char **schemaname, char **refname, char **attname)
 {
+	int			netlevelsup;
 	deparse_namespace *dpns;
 	RangeTblEntry *rte;
 
 	/* Find appropriate nesting depth */
-	if (var->varlevelsup >= list_length(context->namespaces))
-		elog(ERROR, "bogus varlevelsup: %d", var->varlevelsup);
+	netlevelsup = var->varlevelsup + levelsup;
+	if (netlevelsup >= list_length(context->namespaces))
+		elog(ERROR, "bogus varlevelsup: %d offset %d",
+			 var->varlevelsup, levelsup);
 	dpns = (deparse_namespace *) list_nth(context->namespaces,
-										  var->varlevelsup);
+										  netlevelsup);
 
 	/* Find the relevant RTE */
 	if (var->varno >= 1 && var->varno <= list_length(dpns->rtable))
@@ -2467,7 +2474,7 @@ get_names_for_var(Var *var, deparse_context *context,
 											var->varattno-1);
 				if (IsA(aliasvar, Var))
 				{
-					get_names_for_var(aliasvar, context,
+					get_names_for_var(aliasvar, netlevelsup, context,
 									  schemaname, refname, attname);
 					return;
 				}
@@ -2867,7 +2874,7 @@ get_rule_expr(Node *node, deparse_context *context,
 				char	   *refname;
 				char	   *attname;
 
-				get_names_for_var(var, context,
+				get_names_for_var(var, 0, context,
 								  &schemaname, &refname, &attname);
 				if (refname && (context->varprefix || attname == NULL))
 				{
