Check that connection limit is within valid range. IOW, not < -1.

It's missing in older versions too, but it doesn't seem worth
back-porting. All negative are just harmlessly treated as "no limit", and
tightening the check might even brake an application that relies on it.

src/backend/commands/dbcommands.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.218 2009/01/20 18:59:37 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.219 2009/01/30 17:24:47 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -244,7 +244,13 @@ createdb(const CreatedbStmt *stmt)
 		dbctype = strVal(dctype->arg);
 
 	if (dconnlimit && dconnlimit->arg)
+	{
 		dbconnlimit = intVal(dconnlimit->arg);
+		if (dbconnlimit < -1)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid connection limit: %d", dbconnlimit)));
+	}
 
 	/* obtain OID of proposed owner */
 	if (dbowner)
@@ -1319,7 +1325,13 @@ AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel)
 	}
 
 	if (dconnlimit)
+	{
 		connlimit = intVal(dconnlimit->arg);
+		if (connlimit < -1)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid connection limit: %d", connlimit)));
+	}
 
 	/*
 	 * Get the old tuple.  We don't need a lock on the database per se,

src/backend/commands/user.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.185 2009/01/22 20:16:02 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.186 2009/01/30 17:24:47 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -242,7 +242,13 @@ CreateRole(CreateRoleStmt *stmt)
 	if (dcanlogin)
 		canlogin = intVal(dcanlogin->arg) != 0;
 	if (dconnlimit)
+	{
 		connlimit = intVal(dconnlimit->arg);
+		if (connlimit < -1)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid connection limit: %d", connlimit)));
+	}
 	if (daddroleto)
 		addroleto = (List *) daddroleto->arg;
 	if (drolemembers)
@@ -533,7 +539,13 @@ AlterRole(AlterRoleStmt *stmt)
 	if (dcanlogin)
 		canlogin = intVal(dcanlogin->arg);
 	if (dconnlimit)
+	{
 		connlimit = intVal(dconnlimit->arg);
+		if (connlimit < -1)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid connection limit: %d", connlimit)));
+	}
 	if (drolemembers)
 		rolemembers = (List *) drolemembers->arg;
 	if (dvalidUntil)