Fix the Xfer-optimization on the INSERT statement so that it is omitted if

there is a RETURNING clause, since that optimization is not able to deal
with RETURNING.  See [forum:/forumpost/595e132f71|forum thread 595e132f71]
for details.

FossilOrigin-Name: 1d3760a517b8bd2a6be82d2d5788945f49397cdc539fe28fd23e2c0c62a1dbe2

test/insert4.test

@@ -11,7 +11,6 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing the INSERT transfer optimization.
 #
-# $Id: insert4.test,v 1.10 2008/01/21 16:22:46 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -598,6 +597,13 @@ do_test 10.3 {
   set sqlite3_xferopt_count
 } {1}
 
+do_test 10.4 {
+  execsql { PRAGMA integrity_check }
+  set sqlite3_xferopt_count 0
+  execsql { INSERT INTO x     SELECT * FROM t8  RETURNING * }
+  set sqlite3_xferopt_count
+} {0}
+
 #-------------------------------------------------------------------------
 # xfer transfer between tables where the source has an empty partial index.
 #