Fix off-by-one error in autovacuum shmem struct sizing. This could lead to

hlinnaka · hlinnaka · commit 4c22564471e2 · 2008-11-12T10:10:32.000Z
autovacuum worker sending SIGUSR1 signal to wrong process, per Zou Yong's
report.

Backpatch to 8.3.
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
@@ -55,7 +55,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.86 2008/11/03 19:03:41 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.87 2008/11/12 10:10:32 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -222,7 +222,7 @@ typedef enum
 {
 	AutoVacForkFailed,			/* failed trying to start a worker */
 	AutoVacRebalance,			/* rebalance the cost limits */
-	AutoVacNumSignals = AutoVacRebalance		/* must be last */
+	AutoVacNumSignals			/* must be last */
 } AutoVacuumSignal;
 
 /*-------------

Original file line number	Diff line number	Diff line change
`@@ -55,7 +55,7 @@`
`55`	`55`	`*`
`56`	`56`	`*`
`57`	`57`	`* IDENTIFICATION`
`58`		`- * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.86 2008/11/03 19:03:41 alvherre Exp $`
	`58`	`+ * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.87 2008/11/12 10:10:32 heikki Exp $`
`59`	`59`	`*`
`60`	`60`	`*-------------------------------------------------------------------------`
`61`	`61`	`*/`
`@@ -222,7 +222,7 @@ typedef enum`
`222`	`222`	`{`
`223`	`223`	`AutoVacForkFailed, /* failed trying to start a worker */`
`224`	`224`	`AutoVacRebalance, /* rebalance the cost limits */`
`225`		`- AutoVacNumSignals = AutoVacRebalance /* must be last */`
	`225`	`+ AutoVacNumSignals /* must be last */`
`226`	`226`	`} AutoVacuumSignal;`
`227`	`227`
`228`	`228`	`/*-------------`