[sql] Import SQLite 3.17.0.

third_party/sqlite/src/test/backup4.test

 # 2012 October 13
 #
 # The author disclaims copyright to this source code.  In place of
 # a legal notice, here is a blessing:
 #
 #    May you do good and not evil.
 #    May you find forgiveness for yourself and forgive others.
 #    May you share freely, never taking more than you give.
 #
 #***********************************************************************
 #
 # The tests in this file verify that if an empty database (zero bytes in 
 # size) is used as the source of a backup operation, the final destination
 # database is one page in size.
 #
 # The destination must consist of at least one page as truncating a 
 # database file to zero bytes is equivalent to resetting the database
 # schema cookie and change counter. Doing that could cause other clients
 # to become confused and continue using out-of-date cache data.
 #
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
 set testprefix backup4
 
+# The codec logic does not work for zero-length database files.  A database
+# file must contain at least one page in order to be recognized as an
+# encrypted database.
+do_not_use_codec
+
 #-------------------------------------------------------------------------
 # At one point this test was failing because [db] was using an out of
 # date schema in test case 1.2.
 #
 do_execsql_test 1.0 {
   CREATE TABLE t1(x, y, UNIQUE(x, y));
   INSERT INTO t1 VALUES('one', 'two');
   SELECT * FROM t1 WHERE x='one';
   PRAGMA integrity_check;
 } {one two ok}
@@ skipping 58 matching lines @@
 do_test 3.3 {
   sqlite3 db1 test.db2
   db1 backup test.db
   db1 close
   file size test.db
 } {1024}
 
 do_test 3.4 { file size test.db2 } 0
 
 finish_test