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diff --git a/test/walprotocol2.test b/test/walprotocol2.test
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+# 2018 July 4
+#
+# 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.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/wal_common.tcl
+ifcapable !wal {finish_test ; return }
+
+set testprefix walprotocol2
+
+#-------------------------------------------------------------------------
+# When recovering the contents of a WAL file, a process obtains the WRITER
+# lock, then locks all other bytes before commencing recovery. If it fails
+# to lock all other bytes (because some other process is holding a read
+# lock) it should retry up to 100 times. Then return SQLITE_PROTOCOL to the 
+# caller. Test this (test case 1.3).
+#
+# Also test the effect of hitting an SQLITE_BUSY while attempting to obtain
+# the WRITER lock (should be the same). Test case 1.4.
+# 
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE x(y);
+  INSERT INTO x VALUES('z');
+} {wal}
+
+db close
+
+proc lock_callback {method filename handle lock} {
+  # puts "$method $filename $handle $lock"
+}
+testvfs T
+T filter xShmLock 
+T script lock_callback
+
+sqlite3 db  test.db -vfs T
+sqlite3 db2 test.db -vfs T
+
+do_execsql_test 2.0 {
+  SELECT * FROM x;
+} {z}
+do_execsql_test -db db2 2.1 {
+  SELECT * FROM x;
+} {z}
+
+#---------------------------------------------------------------
+# Attempt a "BEGIN EXCLUSIVE" using connection handle [db]. This
+# causes SQLite to open a read transaction, then a write transaction.
+# Rig the xShmLock() callback so that just before the EXCLUSIVE lock
+# for the write transaction is taken, connection [db2] jumps in and
+# modifies the database. This causes the "BEGIN EXCLUSIVE" to throw
+# an SQLITE_BUSY_SNAPSHOT error.
+#
+proc lock_callback {method filename handle lock} {
+  if {$lock=="0 1 lock exclusive"} {
+    proc lock_callback {method filename handle lock} {}
+    db2 eval { INSERT INTO x VALUES('y') }
+  }
+}
+do_catchsql_test 2.2 {
+  BEGIN EXCLUSIVE;
+} {1 {database is locked}}
+do_test 2.3 {
+  sqlite3_extended_errcode db
+} {SQLITE_BUSY}
+
+#---------------------------------------------------------------
+# Same again, but with a busy-handler. This time, following the
+# SQLITE_BUSY_SNAPSHOT error the busy-handler is invoked and then the 
+# whole thing retried from the beginning. This time it succeeds.
+#
+proc lock_callback {method filename handle lock} {
+  if {$lock=="0 1 lock exclusive"} {
+    proc lock_callback {method filename handle lock} {}
+    db2 eval { INSERT INTO x VALUES('x') }
+  }
+}
+db timeout 10
+do_catchsql_test 2.4 {
+  BEGIN EXCLUSIVE;
+} {0 {}}
+do_execsql_test 2.5 {
+  SELECT * FROM x;
+  COMMIT;
+} {z y x}
+
+finish_test