Import SQLite 3.8.7.4.

third_party/sqlite/src/test/sharedlock.test

 # 2009 July 2
 #
 # 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.
 #
 #***********************************************************************
 #
 # $Id: sharedlock.test,v 1.1 2009/07/02 17:21:58 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
+set testprefix sharedlock
 db close
 
 ifcapable !shared_cache {
   finish_test
   return
 }
 
 set ::enable_shared_cache [sqlite3_enable_shared_cache 1]
 sqlite3 db  test.db
 sqlite3 db2 test.db
@@ skipping 14 matching lines @@
 
     # This should fail. Connection [db] has a read-lock on t1, which should
     # prevent connection [db2] from obtaining the write-lock it needs to
     # modify t1. At one point there was a bug causing the previous INSERT
     # to drop the read-lock belonging to [db].
     if {$a == 2} { catch { db2 eval "INSERT INTO t1 VALUES(4, 'four')"  } }
   }
   set res
 } {1 one 2 two 3 three}
 
+
+#-------------------------------------------------------------------------
+# Test that a write-lock is taken on a table when its entire contents
+# are deleted using the OP_Clear optimization.
+#
+foreach {tn delete_sql} {
+  1 { DELETE FROM t2 WHERE 1 }
+  2 { DELETE FROM t2 }
+} {
+  do_execsql_test 2.1 {
+    DROP TABLE IF EXISTS t2;
+    CREATE TABLE t2(x, y);
+    INSERT INTO t2 VALUES(1, 2);
+    INSERT INTO t2 VALUES(3, 4);
+  }
+
+  do_test 2.2 { execsql { SELECT * FROM t2 } db2 } {1 2 3 4}
+
+  do_execsql_test 2.3 " BEGIN; $delete_sql; "
+
+  do_test 2.4 { 
+    catchsql { SELECT * FROM t2 } db2 
+  } {1 {database table is locked: t2}}
+
+  do_execsql_test 2.5 COMMIT
+}
+
+
 db close
 db2 close
-
 sqlite3_enable_shared_cache $::enable_shared_cache
 finish_test
-