transformForUpdate() mustn't assume rowMarks list is initially empty.

tglsfdc · tglsfdc · commit 0a844e84a121 · 2000-12-07T01:12:08.000Z
It could be recursing into a sub-query where there was already a FOR
UPDATE clause.
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$Id: analyze.c,v 1.171 2000/12/06 23:55:19 tgl Exp $
+ *	$Id: analyze.c,v 1.172 2000/12/07 01:12:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2503,6 +2503,7 @@ transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt)
 	return qry;
 }
 
+/* exported so planner can check again after rewriting, query pullup, etc */
 void
 CheckSelectForUpdate(Query *qry)
 {
@@ -2519,7 +2520,7 @@ CheckSelectForUpdate(Query *qry)
 static void
 transformForUpdate(Query *qry, List *forUpdate)
 {
-	List	   *rowMarks = NIL;
+	List	   *rowMarks = qry->rowMarks;
 	List	   *l;
 	List	   *rt;
 	Index		i;
@@ -2542,7 +2543,8 @@ transformForUpdate(Query *qry, List *forUpdate)
 			}
 			else
 			{
-				rowMarks = lappendi(rowMarks, i);
+				if (!intMember(i, rowMarks)) /* avoid duplicates */
+					rowMarks = lappendi(rowMarks, i);
 				rte->checkForWrite = true;
 			}
 		}

Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,7 @@`
`6`	`6`	`* Portions Copyright (c) 1996-2000, PostgreSQL, Inc`
`7`	`7`	`* Portions Copyright (c) 1994, Regents of the University of California`
`8`	`8`	`*`
`9`		`- * $Id: analyze.c,v 1.171 2000/12/06 23:55:19 tgl Exp $`
	`9`	`+ * $Id: analyze.c,v 1.172 2000/12/07 01:12:08 tgl Exp $`
`10`	`10`	`*`
`11`	`11`	`*-------------------------------------------------------------------------`
`12`	`12`	`*/`
`@@ -2503,6 +2503,7 @@ transformAlterTableStmt(ParseState pstate, AlterTableStmt stmt)`
`2503`	`2503`	`return qry;`
`2504`	`2504`	`}`
`2505`	`2505`
	`2506`	`+/* exported so planner can check again after rewriting, query pullup, etc */`
`2506`	`2507`	`void`
`2507`	`2508`	`CheckSelectForUpdate(Query *qry)`
`2508`	`2509`	`{`
`@@ -2519,7 +2520,7 @@ CheckSelectForUpdate(Query *qry)`
`2519`	`2520`	`static void`
`2520`	`2521`	`transformForUpdate(Query qry, List forUpdate)`
`2521`	`2522`	`{`
`2522`		`- List *rowMarks = NIL;`
	`2523`	`+ List *rowMarks = qry->rowMarks;`
`2523`	`2524`	`List *l;`
`2524`	`2525`	`List *rt;`
`2525`	`2526`	`Index i;`
`@@ -2542,7 +2543,8 @@ transformForUpdate(Query qry, List forUpdate)`
`2542`	`2543`	`}`
`2543`	`2544`	`else`
`2544`	`2545`	`{`
`2545`		`- rowMarks = lappendi(rowMarks, i);`
	`2546`	`+ if (!intMember(i, rowMarks)) /* avoid duplicates */`
	`2547`	`+ rowMarks = lappendi(rowMarks, i);`
`2546`	`2548`	`rte->checkForWrite = true;`
`2547`	`2549`	`}`
`2548`	`2550`	`}`