Re: [Tarantool-patches] [PATCH 1/2] lua: turn on lua 5.2 compatibility

[Olga Arkhangelskaia <arkholga@tarantool.org>]

Thanks for the review! I will introduce searate flag to enable some 5.2 
feautures that we strongly need.

16.11.2019 16:47, Igor Munkin пишет:
> Olya,
>
> Thanks for the patch. It proves once again, that we can't just build
> Tarantool with enabled LUAJIT_ENABLE_LUA52COMPAT. Thereby we can't apply
> these changes to 1.10.x / 2.x due to possible users code breakage.
>
> As discussed offline, let's introduce a specific build flag to our LJ
> fork. LUAJIT_ENABLE_PAIRSMM flag is designed to enable only __pairs and
> __ipairs metamethods. There are also several related issues in our
> Github queue (tarantool gh-4560 is the most recent one), thus this flag
> will help us to deliver the frequently requested feature.
>
> On 07.11.19, Olga Arkhangelskaia wrote:
>> Enabling features that might slightly break existing code (os.execute,
>> etc). Done via -DLUAJIT_ENABLE_LUA52COMPAT flag. Now we need to be more
>> attentive with returning values, methametods and etc.
>> ---
>>   cmake/luajit.cmake                    |   1 +
>>   extra/dist/tarantoolctl.in            |   2 +-
>>   test/app-tap/debug.test.lua           |   4 +-
>>   test/app-tap/tarantoolctl.test.lua    |  80 ++---
>>   test/box-tap/cfg.test.lua             |  46 +--
>>   test/wal_off/rtree_benchmark.result   | 255 +++++++++-------
>>   test/wal_off/rtree_benchmark.test.lua |  20 +-
>>   test/wal_off/snapshot_stress.result   | 415 ++++++++++++++------------
>>   test/wal_off/snapshot_stress.test.lua |   4 +-
>>   9 files changed, 450 insertions(+), 377 deletions(-)
>>
>> diff --git a/cmake/luajit.cmake b/cmake/luajit.cmake
>> index 10df633d5..3157c35ac 100644
>> --- a/cmake/luajit.cmake
>> +++ b/cmake/luajit.cmake
>> @@ -217,6 +217,7 @@ macro(luajit_build)
>>           add_definitions(-DLUAJIT_USE_ASAN=1)
>>           set (luajit_ldflags ${luajit_ldflags} -fsanitize=address)
>>       endif()
>> +    add_definitions(-DLUAJIT_ENABLE_LUA52COMPAT=1)
>>       add_definitions(-DLUAJIT_SMART_STRINGS=1)
>>       # Add all COMPILE_DEFINITIONS to xcflags
>>       get_property(defs DIRECTORY PROPERTY COMPILE_DEFINITIONS)
>> diff --git a/extra/dist/tarantoolctl.in b/extra/dist/tarantoolctl.in
>> index 6daf866ac..e8c9ff164 100755
>> --- a/extra/dist/tarantoolctl.in
>> +++ b/extra/dist/tarantoolctl.in
>> @@ -309,7 +309,7 @@ local function under_systemd()
>>       if not usermode then
>>           local rv = os.execute("systemctl 2>/dev/null | grep '\\-\\.mount' " ..
>>                                 "1>/dev/null 2>/dev/null")
>> -        if rv == 0 then
>> +        if rv == true then
>>               return true
>>           end
>>       end
>> diff --git a/test/app-tap/debug.test.lua b/test/app-tap/debug.test.lua
>> index 0d199e55b..eee932acc 100755
>> --- a/test/app-tap/debug.test.lua
>> +++ b/test/app-tap/debug.test.lua
>> @@ -61,7 +61,7 @@ for _, test in ipairs(tests) do
>>       local cmd = string.format('%s -e "%s; os.exit(0)"', TNTBIN, test)
>>       print('Exec: '..cmd)
>>       io.flush()
>> -    assert(os.execute(cmd) == 0, string.format('cmd: "%s" must execute successfully', cmd))
>> +    assert(os.execute(cmd) == true, string.format('cmd: "%s" must execute successfully', cmd))
>>   end
>>   
>>   local fio = require('fio')
>> @@ -87,7 +87,7 @@ for _, test in ipairs(tests) do
>>       file:close()
>>       print('Source: '..test)
>>       io.flush()
>> -    assert(os.execute(cmd) == 0, string.format('cmd: "%s" must execute successfully', cmd))
>> +    assert(os.execute(cmd) == true, string.format('cmd: "%s" must execute successfully', cmd))
>>   end
>>   
>>   os.remove(filename)
>> diff --git a/test/app-tap/tarantoolctl.test.lua b/test/app-tap/tarantoolctl.test.lua
>> index f38820805..ea780fe07 100755
>> --- a/test/app-tap/tarantoolctl.test.lua
>> +++ b/test/app-tap/tarantoolctl.test.lua
>> @@ -84,10 +84,10 @@ local function run_command(dir, command)
>>       local fstderr = fio.pathjoin(dir, 'stderr-' .. suffix)
>>       local line = [[/bin/sh -c 'cd "%s" && %s >"%s" 2>"%s"']]
>>       line = line:format(dir, command, fstdout, fstderr)
>> -    local res = os.execute(line)
>> +    local res, exit, status = os.execute(line)
>>       local fstdout_e, fstderr_e = io.open(fstdout):read('*a'), io.open(fstderr):read('*a')
>>       fio.unlink(fstdout); fio.unlink(fstderr);
>> -    return res/256, fstdout_e, fstderr_e
>> +    return res, status, fstdout_e, fstderr_e
>>   end
>>   
>>   local function tctl_wait_start(dir, name)
>> @@ -133,13 +133,19 @@ local function tctl_command(dir, cmd, args, name)
>>       return run_command(dir, command)
>>   end
>>   
>> -local function check_ok(test, dir, cmd, args, e_res, e_stdout, e_stderr)
>> -    local res, stdout, stderr = tctl_command(dir, cmd, args)
>> +local FAIL = nil
>> +local SUCCESS = true
>> +
>> +local function check_ok(test, dir, cmd, args, e_res, e_status, e_stdout, e_stderr)
>> +    local res, status, stdout, stderr = tctl_command(dir, cmd, args)
>>       stdout, stderr = stdout or '', stderr or ''
>>       local ares = true
>>       if (e_res ~= nil) then
>>           local val = test:is(res, e_res, ("check '%s' command status for '%s'"):format(cmd,args))
>>           ares = ares and val
>> +    else
>> +        local val = test:is(status, e_status, ("check '%s' command status for '%s'"):format(cmd,args))
>> +        ares = ares and val
>>       end
>>       if e_stdout ~= nil then
>>           local val = test:is(res, e_res, ("check '%s' stdout for '%s'"):format(cmd,args))
>> @@ -190,17 +196,17 @@ do
>>       local status, err = pcall(function()
>>           test:test("basic test", function(test_i)
>>               test_i:plan(18)
>> -            check_ok(test_i, dir, 'start', 'delayed_box_cfg', 0, nil, "Starting instance")
>> -            check_ok(test_i, dir, 'start',  'script', 0, nil, "Starting instance")
>> +            check_ok(test_i, dir, 'start', 'delayed_box_cfg', SUCCESS, 0, nil, "Starting instance")
>> +            check_ok(test_i, dir, 'start',  'script', SUCCESS, 0, nil, "Starting instance")
>>               tctl_wait_start(dir, 'script')
>> -            check_ok(test_i, dir, 'status', 'script', 0, nil, "is running")
>> -            check_ok(test_i, dir, 'start',  'script', 1, nil, "is already running")
>> -            check_ok(test_i, dir, 'status', 'script', 0, nil, "is running")
>> -            check_ok(test_i, dir, 'stop',   'script', 0, nil, "Stopping")
>> +            check_ok(test_i, dir, 'status', 'script', SUCCESS, 0, nil, "is running")
>> +            check_ok(test_i, dir, 'start',  'script', FAIL, 1, nil, "is already running")
>> +            check_ok(test_i, dir, 'status', 'script', SUCCESS, 0, nil, "is running")
>> +            check_ok(test_i, dir, 'stop',   'script', SUCCESS, 0, nil, "Stopping")
>>               tctl_wait_stop(dir, 'script')
>> -            check_ok(test_i, dir, 'status', 'script', 1, nil, "is stopped")
>> -            check_ok(test_i, dir, 'stop',   'script', 0, nil, "is not running")
>> -            check_ok(test_i, dir, 'status', 'script', 1, nil, "is stopped" )
>> +            check_ok(test_i, dir, 'status', 'script', FAIL, 1, nil, "is stopped")
>> +            check_ok(test_i, dir, 'stop',   'script', SUCCESS, 0, nil, "is not running")
>> +            check_ok(test_i, dir, 'status', 'script', FAIL, 1, nil, "is stopped" )
>>           end)
>>       end)
>>   
>> @@ -225,16 +231,16 @@ do
>>       local status, err = pcall(function()
>>           test:test("basic test for bad script", function(test_i)
>>               test_i:plan(7)
>> -            check_ok(test_i, dir, 'start', 'script', 1, nil,
>> +            check_ok(test_i, dir, 'start', 'script', FAIL, 1, nil,
>>                        'Instance script is not found')
>> -            check_ok(test_i, dir, 'start', 'bad_script', 1, nil,
>> +            check_ok(test_i, dir, 'start', 'bad_script', FAIL,1, nil,
>>                        'unexpected symbol near')
>> -            check_ok(test_i, dir, 'start', 'good_script', 0)
>> +            check_ok(test_i, dir, 'start', 'good_script', SUCCESS, 0)
>>               tctl_wait_start(dir, 'good_script')
>>               -- wait here
>> -            check_ok(test_i, dir, 'eval',  'good_script bad_script.lua', 3,
>> +            check_ok(test_i, dir, 'eval',  'good_script bad_script.lua', FAIL, 3,
>>                        nil, nil)
>> -            check_ok(test_i, dir, 'stop', 'good_script', 0)
>> +            check_ok(test_i, dir, 'stop', 'good_script', SUCCESS, 0)
>>           end)
>>       end)
>>   
>> @@ -261,13 +267,13 @@ do
>>       local status, err = pcall(function()
>>           test:test("check answers in case of call", function(test_i)
>>               test_i:plan(5)
>> -            check_ok(test_i, dir, 'start', 'good_script', 0)
>> +            check_ok(test_i, dir, 'start', 'good_script', SUCCESS, 0)
>>               tctl_wait_start(dir, 'good_script')
>> -            check_ok(test_i, dir, 'eval',  'good_script bad_script.lua', 3,
>> +            check_ok(test_i, dir, 'eval',  'good_script bad_script.lua', FAIL, 3,
>>                        nil, nil)
>> -            check_ok(test_i, dir, 'eval',  'good_script ok_script.lua', 0,
>> +            check_ok(test_i, dir, 'eval',  'good_script ok_script.lua', SUCCESS, 0,
>>                        '---\n- 1\n...', nil)
>> -            check_ok(test_i, dir, 'stop', 'good_script', 0)
>> +            check_ok(test_i, dir, 'stop', 'good_script', SUCCESS, 0)
>>           end)
>>       end)
>>   
>> @@ -290,21 +296,21 @@ do
>>       local status, err = pcall(function()
>>           test:test("check error codes in case of enter", function(test_i)
>>               test_i:plan(10)
>> -            check_ok(test_i, dir, 'enter', 'script', 1, nil, "Can't connect to")
>> +            check_ok(test_i, dir, 'enter', 'script', FAIL, 1, nil, "Can't connect to")
>>               local console_sock = 'script.control'
>>               console_sock = fio.pathjoin(dir, console_sock)
>>               test_i:is(fio.path.exists(console_sock), false, "directory clean")
>> -            check_ok(test_i, dir, 'start', 'script', 0)
>> +            check_ok(test_i, dir, 'start', 'script', SUCCESS, 0)
>>               tctl_wait_start(dir, 'script')
>>               test_i:is(fio.path.exists(console_sock), true,
>>                         "unix socket created")
>> -            check_ok(test_i, dir, 'stop', 'script', 0)
>> +            check_ok(test_i, dir, 'stop', 'script', SUCCESS, 0)
>>               tctl_wait_stop(dir, 'script')
>>               test_i:is(fio.path.exists(console_sock), false,
>>                         "remove unix socket upon exit")
>>               fio.open(console_sock, 'O_CREAT')
>>               test_i:is(fio.path.exists(console_sock), true, "file created")
>> -            check_ok(test_i, dir, 'enter', 'script', 1, nil, "Can't connect to")
>> +            check_ok(test_i, dir, 'enter', 'script', FAIL, 1, nil, "Can't connect to")
>>               fio.unlink(console_sock)
>>           end)
>>       end)
>> @@ -325,7 +331,7 @@ do
>>       local function test_help(test, dir, cmd, e_stderr)
>>           local desc = dir and 'with config' or 'without config'
>>           dir = dir or './'
>> -        local res, stdout, stderr = run_command(dir, cmd)
>> +        local res, status, stdout, stderr = run_command(dir, cmd)
>>           if e_stderr ~= nil then
>>               if not test:ok(stderr:find(e_stderr), ("check stderr of '%s' %s"):format(cmd, desc)) then
>>                   print(("Expected to find '%s' in '%s'"):format(e_stderr, stderr))
>> @@ -380,8 +386,8 @@ do
>>           local command_base = 'tarantoolctl cat filler/00000000000000000000.xlog'
>>           local desc = args and "cat + " .. args or "cat"
>>           args = args and " " .. args or ""
>> -        local res, stdout, stderr = run_command(dir, command_base .. args)
>> -        test:is(res, 0, desc .. " result")
>> +        local res, status, stdout, stderr = run_command(dir, command_base .. args)
>> +        test:is(res, SUCCESS, desc .. " result")
>>           test:is(select(2, stdout:gsub(delim, delim)), lc, desc .. " line count")
>>       end
>>   
>> @@ -389,15 +395,15 @@ do
>>           local command_base = 'tarantoolctl cat filler/00000000000000000000.snap'
>>           local desc = args and "cat + " .. args or "cat"
>>           args = args and " " .. args or ""
>> -        local res, stdout, stderr = run_command(dir, command_base .. args)
>> -        test:is(res, 0, desc .. " result")
>> +        local res, status, stdout, stderr = run_command(dir, command_base .. args)
>> +        test:is(res, SUCCESS, desc .. " result")
>>           test:is(select(2, stdout:gsub(delim, delim)), lc, desc .. " line count")
>>       end
>>   
>>       local status, err = pcall(function()
>>           test:test("fill and test cat output", function(test_i)
>>               test_i:plan(29)
>> -            check_ok(test_i, dir, 'start', 'filler', 0)
>> +            check_ok(test_i, dir, 'start', 'filler', SUCCESS, 0)
>>               check_ctlcat_xlog(test_i, dir, nil, "---\n", 7)
>>               check_ctlcat_xlog(test_i, dir, "--space=512", "---\n", 6)
>>               check_ctlcat_xlog(test_i, dir, "--space=666", "---\n", 0)
>> @@ -470,14 +476,14 @@ else
>>       local status, err = pcall(function()
>>           test:test("fill and test play output", function(test_i)
>>               test_i:plan(6)
>> -            check_ok(test_i, dir, 'start', 'filler', 0)
>> +            check_ok(test_i, dir, 'start', 'filler', SUCCESS, 0)
>>               local lsn_before = test_run:get_lsn("remote", 1)
>>               test_i:is(lsn_before, 4, "check lsn before")
>> -            local res, stdout, stderr = run_command(dir, command_base)
>> -            test_i:is(res, 0, "execution result")
>> +            local res, status, stdout, stderr = run_command(dir, command_base)
>> +            test_i:is(res, SUCCESS, "execution result")
>>               test_i:is(test_run:get_lsn("remote", 1), 10, "check lsn after")
>> -            local res, stdout, stderr = run_command(dir, command_base)
>> -            test_i:is(res, 0, "execution result")
>> +            local res, status, stdout, stderr = run_command(dir, command_base)
>> +            test_i:is(res, SUCCESS, "execution result")
>>               test_i:is(test_run:get_lsn("remote", 1), 16, "check lsn after")
>>           end)
>>       end)
>> diff --git a/test/box-tap/cfg.test.lua b/test/box-tap/cfg.test.lua
>> index d529447bb..b61073438 100755
>> --- a/test/box-tap/cfg.test.lua
>> +++ b/test/box-tap/cfg.test.lua
>> @@ -162,7 +162,7 @@ box.cfg({ worker_pool_threads = 1})
>>   test:is(box.cfg.worker_pool_threads, 1, 'worker_pool_threads')
>>   
>>   local tarantool_bin = arg[-1]
>> -local PANIC = 256
>> +local PANIC = nil
>>   function run_script(code)
>>       local dir = fio.tempdir()
>>       local script_path = fio.pathjoin(dir, 'script.lua')
>> @@ -182,14 +182,14 @@ code =[[
>>   box.cfg{vinyl_memory=0}
>>   os.exit(box.cfg.vinyl_memory == 0 and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "actually set vinyl_memory to 0")
>> +test:is(run_script(code), true, "actually set vinyl_memory to 0")
>>   
>>   -- gh-715: Cannot switch to/from 'fsync'
>>   code = [[ box.cfg{ log="tarantool.log", log_nonblock = false, wal_mode = 'fsync' }; ]]
>> -test:is(run_script(code), 0, 'wal_mode fsync')
>> +test:is(run_script(code), true, 'wal_mode fsync')
>>   
>>   code = [[ box.cfg{ wal_mode = 'fsync' }; box.cfg { wal_mode = 'fsync' }; ]]
>> -test:is(run_script(code), 0, 'wal_mode fsync -> fsync')
>> +test:is(run_script(code), true, 'wal_mode fsync -> fsync')
>>   
>>   code = [[ box.cfg{ wal_mode = 'fsync' }; box.cfg { wal_mode = 'none'} ]]
>>   test:is(run_script(code), PANIC, 'wal_mode fsync -> write is not supported')
>> @@ -204,7 +204,7 @@ test:is(run_script(code), PANIC, 'work_dir is invalid')
>>   
>>   -- gh-2664: vinyl_dir is checked on the first use
>>   code = [[ box.cfg{ vinyl_dir='invalid' } ]]
>> -test:is(run_script(code), 0, 'vinyl_dir is invalid')
>> +test:is(run_script(code), true, 'vinyl_dir is invalid')
>>   
>>   code = [[ box.cfg{ memtx_dir='invalid' } ]]
>>   test:is(run_script(code), PANIC, 'snap_dir is invalid')
>> @@ -217,7 +217,7 @@ code = [[
>>   box.cfg{log_nonblock = false }
>>   os.exit(box.cfg.log_nonblock == false and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "log_nonblock new value")
>> +test:is(run_script(code), true, "log_nonblock new value")
>>   
>>   -- gh-3048: box.cfg must not crash on invalid log configuration
>>   code = [[ box.cfg{ log = '/' } ]]
>> @@ -265,7 +265,7 @@ local conn = require('net.box').connect('unix/:./tarantool.sock',
>>   if not conn:ping() then os.exit(1) end
>>   os.exit(0)
>>   ]]
>> -test:is(run_script(code), 0, "wal_mode none and ER_LOADING")
>> +test:is(run_script(code), true, "wal_mode none and ER_LOADING")
>>   
>>   --
>>   -- gh-1962: incorrect replication source
>> @@ -286,13 +286,13 @@ code = [[
>>   box.cfg{vinyl_page_size = 1 * 1024 * 1024, vinyl_range_size = 2 * 1024 * 1024}
>>   os.exit(0)
>>   ]]
>> -test:is(run_script(code), 0, "page size less than range")
>> +test:is(run_script(code), true, "page size less than range")
>>   
>>   code = [[
>>   box.cfg{vinyl_page_size = 2 * 1024 * 1024, vinyl_range_size = 2 * 1024 * 1024}
>>   os.exit(0)
>>   ]]
>> -test:is(run_script(code), 0, "page size equal with range")
>> +test:is(run_script(code), true, "page size equal with range")
>>   
>>   -- test memtx options upgrade
>>   code = [[
>> @@ -303,7 +303,7 @@ os.exit(box.cfg.memtx_memory == 214748364
>>       and box.cfg.memtx_max_tuple_size == 64 * 1024
>>   and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "upgrade memtx memory options")
>> +test:is(run_script(code), true, "upgrade memtx memory options")
>>   
>>   code = [[
>>   box.cfg{slab_alloc_arena = 0.2, slab_alloc_minimal = 16, slab_alloc_maximal = 64 * 1024,
>> @@ -311,7 +311,7 @@ box.cfg{slab_alloc_arena = 0.2, slab_alloc_minimal = 16, slab_alloc_maximal = 64
>>       memtx_max_tuple_size = 64 * 1024}
>>   os.exit(0)
>>   ]]
>> -test:is(run_script(code), 0, "equal new and old memtx options")
>> +test:is(run_script(code), true, "equal new and old memtx options")
>>   
>>   code = [[
>>   box.cfg{slab_alloc_arena = 0.2, slab_alloc_minimal = 16, slab_alloc_maximal = 64 * 1024,
>> @@ -339,20 +339,20 @@ code = [[
>>   box.cfg{panic_on_wal_error = true}
>>   os.exit(box.cfg.force_recovery == false and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "panic_on_wal_error")
>> +test:is(run_script(code), true, "panic_on_wal_error")
>>   
>>   code = [[
>>   box.cfg{panic_on_snap_error = false}
>>   os.exit(box.cfg.force_recovery == true and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "panic_on_snap_error")
>> +test:is(run_script(code), true, "panic_on_snap_error")
>>   
>>   code = [[
>>   box.cfg{snapshot_period = 100, snapshot_count = 4}
>>   os.exit(box.cfg.checkpoint_interval == 100
>>         and box.cfg.checkpoint_count == 4 and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "setup checkpoint params")
>> +test:is(run_script(code), true, "setup checkpoint params")
>>   
>>   code = [[
>>   box.cfg{snapshot_period = 100, snapshot_count = 4}
>> @@ -360,7 +360,7 @@ box.cfg{snapshot_period = 150, snapshot_count = 8}
>>   os.exit(box.cfg.checkpoint_interval == 150
>>         and box.cfg.checkpoint_count == 8 and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "update checkpoint params")
>> +test:is(run_script(code), true, "update checkpoint params")
>>   
>>   --
>>   --  test wal_max_size option
>> @@ -378,7 +378,7 @@ end
>>   cnt2 = #fio.glob(fio.pathjoin(box.cfg.wal_dir, '*.xlog'))
>>   os.exit(cnt1 < cnt2 - 8 and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "wal_max_size xlog rotation")
>> +test:is(run_script(code), true, "wal_max_size xlog rotation")
>>   
>>   --
>>   -- gh-2872 bootstrap is aborted if vinyl_dir contains vylog files
>> @@ -422,7 +422,7 @@ ok = ok and not pcall(s.insert, s, {1})
>>   ok = ok and pcall(s.select, s)
>>   os.exit(ok and 0 or 1)
>>   ]], cfg)
>> -test:is(run_script(code), 0, "wal_mode none -> vinyl DDL/DML is not supported")
>> +test:is(run_script(code), true, "wal_mode none -> vinyl DDL/DML is not supported")
>>   fio.rmtree(dir)
>>   
>>   --
>> @@ -441,13 +441,13 @@ instance_uuid = tostring(require('uuid').new())
>>   box.cfg{instance_uuid = instance_uuid}
>>   os.exit(instance_uuid == box.info.uuid and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "check instance_uuid")
>> +test:is(run_script(code), true, "check instance_uuid")
>>   code = [[
>>   replicaset_uuid = tostring(require('uuid').new())
>>   box.cfg{replicaset_uuid = replicaset_uuid}
>>   os.exit(replicaset_uuid == box.info.cluster.uuid and 0 or 1)
>>   ]]
>> -test:is(run_script(code), 0, "check replicaset_uuid")
>> +test:is(run_script(code), true, "check replicaset_uuid")
>>   
>>   --
>>   -- Configuration fails on instance or replica set UUID mismatch.
>> @@ -498,7 +498,7 @@ unix_socket:close()
>>   os.remove(path)
>>   os.exit(res)
>>   ]]
>> -test:is(run_script(code), 0, "unix socket syslog log configuration")
>> +test:is(run_script(code), true, "unix socket syslog log configuration")
>>   
>>   --
>>   -- Check syslog remote configuration
>> @@ -540,7 +540,7 @@ end
>>   sc:close()
>>   os.exit(res)
>>   ]]
>> -test:is(run_script(code), 0, "remote syslog log configuration")
>> +test:is(run_script(code), true, "remote syslog log configuration")
>>   
>>   --
>>   -- gh-3615: check that log_nonblock is not lost
>> @@ -563,7 +563,7 @@ unix_socket:close()
>>   os.remove(path)
>>   os.exit(0)
>>   ]]
>> -test:is(run_script(code), 0, "log_nonblock")
>> +test:is(run_script(code), true, "log_nonblock")
>>   
>>   --
>>   -- Crash (instead of panic) when trying to recover a huge tuple.
>> @@ -580,7 +580,7 @@ code2 = string.format([[
>>   box.cfg{wal_dir = '%s', memtx_dir = '%s', memtx_max_tuple_size = 10 * 1024}
>>   os.exit(0)
>>   ]], dir, dir)
>> -test:is(run_script(code1), 0, "create huge tuple")
>> +test:is(run_script(code1), true, "create huge tuple")
>>   test:is(run_script(code2), PANIC, "panic on huge tuple recovery")
>>   fio.rmtree(dir)
>>   
>> diff --git a/test/wal_off/rtree_benchmark.result b/test/wal_off/rtree_benchmark.result
>> index 8e01c9f2a..bdcf98b5d 100644
>> --- a/test/wal_off/rtree_benchmark.result
>> +++ b/test/wal_off/rtree_benchmark.result
>> @@ -1,59 +1,67 @@
>> +-- test-run result file version 2
>>   n_records = 10000
>> ----
>> -...
>> + | ---
>> + | ...
>>   n_iterations = 10000
>> ----
>> -...
>> + | ---
>> + | ...
>>   n_neighbors = 10
>> ----
>> -...
>> + | ---
>> + | ...
>>   env = require('test_run')
>> ----
>> -...
>> + | ---
>> + | ...
>>   test_run = env.new()
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   file = io.open("rtree_benchmark.res", "w")
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   s = box.schema.space.create('rtreebench')
>> ----
>> -...
>> + | ---
>> + | ...
>>   _ = s:create_index('primary')
>> ----
>> -...
>> + | ---
>> + | ...
>>   _ = s:create_index('spatial', { type = 'rtree', unique = false, parts = {2, 'array'}})
>> ----
>> -...
>> -file:write(" *** 2D *** \n")
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +
>> +file:write(" *** 2D *** \n") ~= nil;
>> + | ---
>> + | - true
>> + | ...
>>   rect_width = 180 / math.pow(n_records, 1 / 2)
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   start = os.time()
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   test_run:cmd("setopt delimiter ';'")
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>>   for i = 1, n_records do
>>      s:insert{i,{180*math.random(),180*math.random()}}
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +
>> +file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>>   n = 0;
>> ----
>> -...
>> + | ---
>> + | ...
>>   for i = 1, n_iterations do
>>      x = (180 - rect_width) * math.random()
>>      y = (180 - rect_width) * math.random()
>> @@ -61,15 +69,16 @@ for i = 1, n_iterations do
>>          n = n + 1
>>      end
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>>   n = 0
>>   for i = 1, n_iterations do
>>      x = 180 * math.random()
>> @@ -78,45 +87,54 @@ for i = 1, n_iterations do
>>         n = n + 1
>>      end
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>>   for i = 1, n_records do
>>       s:delete{i}
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   s:drop();
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   dimension = 8;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   s = box.schema.space.create('rtreebench');
>> ----
>> -...
>> + | ---
>> + | ...
>>   _ = s:create_index('primary');
>> ----
>> -...
>> + | ---
>> + | ...
>>   _ = s:create_index('spatial', { type = 'rtree', unique = false, parts = {2, 'array'}, dimension = dimension});
>> ----
>> -...
>> -file:write(" *** 8D *** \n")
>> + | ---
>> + | ...
>> +
>> +file:write(" *** 8D *** \n") ~= nil;
>> + | ---
>> + | - true
>> + | ...
>>   rect_width = 180 / math.pow(n_records, 1 / dimension)
>>   
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   for i = 1, n_records do
>>      local record = {}
>>      for j = 1, dimension do
>> @@ -124,18 +142,20 @@ for i = 1, n_records do
>>      end
>>      s:insert{i,record}
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +
>> +file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>>   n = 0;
>> ----
>> -...
>> + | ---
>> + | ...
>>   for i = 1, n_iterations do
>>      local rect = {}
>>      for j = 1, dimension do
>> @@ -148,15 +168,16 @@ for i = 1, n_iterations do
>>          n = n + 1
>>      end
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>>   n = 0
>>   for i = 1, 0 do
>>      local rect = {}
>> @@ -167,32 +188,38 @@ for i = 1, 0 do
>>         n = n + 1
>>      end
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   start = os.time();
>> ----
>> -...
>> + | ---
>> + | ...
>>   for i = 1, n_records do
>>       s:delete{i}
>>   end;
>> ----
>> -...
>> -file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start));
>> ----
>> -- true
>> -...
>> + | ---
>> + | ...
>> +file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start)) ~= nil;
>> + | ---
>> + | - true
>> + | ...
>> +
>>   s:drop();
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   file:close();
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>> +
>>   test_run:cmd("setopt delimiter ''");
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>> +
>> +
>> diff --git a/test/wal_off/rtree_benchmark.test.lua b/test/wal_off/rtree_benchmark.test.lua
>> index 6fae977c9..aa58624d1 100644
>> --- a/test/wal_off/rtree_benchmark.test.lua
>> +++ b/test/wal_off/rtree_benchmark.test.lua
>> @@ -10,7 +10,7 @@ s = box.schema.space.create('rtreebench')
>>   _ = s:create_index('primary')
>>   _ = s:create_index('spatial', { type = 'rtree', unique = false, parts = {2, 'array'}})
>>   
>> -file:write(" *** 2D *** \n")
>> +file:write(" *** 2D *** \n") ~= nil;
>>   rect_width = 180 / math.pow(n_records, 1 / 2)
>>   
>>   start = os.time()
>> @@ -20,7 +20,7 @@ for i = 1, n_records do
>>      s:insert{i,{180*math.random(),180*math.random()}}
>>   end;
>>   
>> -file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start));
>> +file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start)) ~= nil;
>>   
>>   start = os.time();
>>   n = 0;
>> @@ -31,7 +31,7 @@ for i = 1, n_iterations do
>>          n = n + 1
>>      end
>>   end;
>> -file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start));
>> +file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start)) ~= nil;
>>   
>>   start = os.time();
>>   n = 0
>> @@ -42,13 +42,13 @@ for i = 1, n_iterations do
>>         n = n + 1
>>      end
>>   end;
>> -file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start));
>> +file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start)) ~= nil;
>>   
>>   start = os.time();
>>   for i = 1, n_records do
>>       s:delete{i}
>>   end;
>> -file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start));
>> +file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start)) ~= nil;
>>   
>>   s:drop();
>>   
>> @@ -58,7 +58,7 @@ s = box.schema.space.create('rtreebench');
>>   _ = s:create_index('primary');
>>   _ = s:create_index('spatial', { type = 'rtree', unique = false, parts = {2, 'array'}, dimension = dimension});
>>   
>> -file:write(" *** 8D *** \n")
>> +file:write(" *** 8D *** \n") ~= nil;
>>   rect_width = 180 / math.pow(n_records, 1 / dimension)
>>   
>>   start = os.time();
>> @@ -71,7 +71,7 @@ for i = 1, n_records do
>>      s:insert{i,record}
>>   end;
>>   
>> -file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start));
>> +file:write(string.format("Elapsed time for inserting %d records: %d\n", n_records, os.time() - start)) ~= nil;
>>   
>>   start = os.time();
>>   n = 0;
>> @@ -87,7 +87,7 @@ for i = 1, n_iterations do
>>          n = n + 1
>>      end
>>   end;
>> -file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start));
>> +file:write(string.format("Elapsed time for %d belongs searches selecting %d records: %d\n", n_iterations, n, os.time() - start)) ~= nil;
>>   
>>   start = os.time();
>>   n = 0
>> @@ -100,13 +100,13 @@ for i = 1, 0 do
>>         n = n + 1
>>      end
>>   end;
>> -file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start));
>> +file:write(string.format("Elapsed time for %d nearest %d neighbors searches selecting %d records: %d\n", n_iterations, n_neighbors, n, os.time() - start)) ~= nil;
>>   
>>   start = os.time();
>>   for i = 1, n_records do
>>       s:delete{i}
>>   end;
>> -file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start));
>> +file:write(string.format("Elapsed time for deleting  %d records: %d\n", n_records, os.time() - start)) ~= nil;
>>   
>>   s:drop();
>>   
>> diff --git a/test/wal_off/snapshot_stress.result b/test/wal_off/snapshot_stress.result
>> index 29cea8c04..f9f17441d 100644
>> --- a/test/wal_off/snapshot_stress.result
>> +++ b/test/wal_off/snapshot_stress.result
>> @@ -1,174 +1,186 @@
>> +-- test-run result file version 2
>>   -- The test emulates account system. There are increasing number or accounts
>>   -- and a lot of double entry transactions are made that moving random
>>   -- ammount from random account to another random accont.
>>   -- Snapshots are made every snapshot_interval seconds and then checked for consistency
>>   env = require('test_run')
>> ----
>> -...
>> + | ---
>> + | ...
>>   test_run = env.new()
>> ----
>> -...
>> + | ---
>> + | ...
>>   -- Settings: You may increase theese value to make test longer
>>   -- number of worker fibers:
>>   workers_count = 80
>> ----
>> -...
>> + | ---
>> + | ...
>>   -- number of iterations per fiber (operations + add new account + add space)
>>   iteration_count = 8
>> ----
>> -...
>> + | ---
>> + | ...
>>   -- number of operations per iterations
>>   operation_count = 8
>> ----
>> -...
>> + | ---
>> + | ...
>>   -- limit of random string length in every account
>>   string_max_size = 128
>> ----
>> -...
>> + | ---
>> + | ...
>>   -- initial number of accounts
>>   accounts_start = 5
>> ----
>> -...
>> + | ---
>> + | ...
>>   -- delay between snapshots
>>   snapshot_interval = 0.005
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   fiber = require('fiber')
>> ----
>> -...
>> + | ---
>> + | ...
>>   fio = require('fio')
>> ----
>> -...
>> + | ---
>> + | ...
>>   log = require('log')
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   tarantool_bin_path = arg[-1]
>> ----
>> -...
>> + | ---
>> + | ...
>>   work_dir = fio.cwd()
>> ----
>> -...
>> + | ---
>> + | ...
>>   script_path = fio.pathjoin(work_dir, 'snap_script.lua')
>> ----
>> -...
>> + | ---
>> + | ...
>>   cmd_template = [[/bin/sh -c 'cd "%s" && "%s" ./snap_script.lua 2> /dev/null']]
>> ----
>> -...
>> + | ---
>> + | ...
>>   cmd = string.format(cmd_template, work_dir, tarantool_bin_path)
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   open_flags = {'O_CREAT', 'O_WRONLY', 'O_TRUNC'}
>> ----
>> -...
>> + | ---
>> + | ...
>>   script = fio.open(script_path, open_flags, tonumber('0777', 8))
>> ----
>> -...
>> + | ---
>> + | ...
>>   script:write("os.exit(-1)")
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>>   script:close()
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>>   res = os.execute(cmd)
>> ----
>> -...
>> + | ---
>> + | ...
>>   str_res = 'precheck ' .. (res ~= 0 and ' ok(1)' or 'failed(1)')
>> ----
>> -...
>> + | ---
>> + | ...
>>   str_res
>> ----
>> -- precheck  ok(1)
>> -...
>> + | ---
>> + | - precheck  ok(1)
>> + | ...
>> +
>>   script = fio.open(script_path, open_flags, tonumber('0777', 8))
>> ----
>> -...
>> + | ---
>> + | ...
>>   script:write("os.exit(0)")
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>>   script:close()
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>>   res = os.execute(cmd)
>> ----
>> -...
>> -str_res = 'precheck ' .. (res == 0 and ' ok(2)' or 'failed(2)')
>> ----
>> -...
>> + | ---
>> + | ...
>> +str_res = 'precheck ' .. (res == true and ' ok(2)' or 'failed(2)')
>> + | ---
>> + | ...
>>   str_res
>> ----
>> -- precheck  ok(2)
>> -...
>> + | ---
>> + | - precheck  ok(2)
>> + | ...
>> +
>>   snap_search_wildcard = fio.pathjoin(box.cfg.memtx_dir, '*.snap');
>> ----
>> -...
>> + | ---
>> + | ...
>>   snaps = fio.glob(snap_search_wildcard);
>> ----
>> -...
>> + | ---
>> + | ...
>>   initial_snap_count = #snaps
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   if box.space.accounts then box.space.accounts:drop() end
>> ----
>> -...
>> + | ---
>> + | ...
>>   if box.space.operations then box.space.operations:drop() end
>> ----
>> -...
>> + | ---
>> + | ...
>>   if box.space.deleting then box.space.deleting:drop() end
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   s1 = box.schema.create_space("accounts")
>> ----
>> -...
>> + | ---
>> + | ...
>>   i1 = s1:create_index('primary', { type = 'HASH', parts = {1, 'unsigned'} })
>> ----
>> -...
>> + | ---
>> + | ...
>>   s2 = box.schema.create_space("operations")
>> ----
>> -...
>> + | ---
>> + | ...
>>   i2 = s2:create_index('primary', { type = 'HASH', parts = {1, 'unsigned'} })
>> ----
>> -...
>> + | ---
>> + | ...
>>   s3 = box.schema.create_space("deleting")
>> ----
>> -...
>> + | ---
>> + | ...
>>   i3 = s3:create_index('primary', { type = 'TREE', parts = {1, 'unsigned'} })
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   n_accs = 0
>> ----
>> -...
>> + | ---
>> + | ...
>>   n_ops = 0
>> ----
>> -...
>> + | ---
>> + | ...
>>   n_spaces = 0
>> ----
>> -...
>> + | ---
>> + | ...
>>   workers_done = 0
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   test_run:cmd("setopt delimiter ';'")
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>>   garbage = {};
>> ----
>> -...
>> + | ---
>> + | ...
>>   str = ""
>>   for i = 1,string_max_size do
>>       str = str .. '-' garbage[i - 1] = str
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function get_new_space_name()
>>       n_spaces = n_spaces + 1
>>       return "test" .. tostring(n_spaces - 1)
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   tmp = get_new_space_name()
>>   if box.space[tmp] then box.space[tmp]:drop() tmp = get_new_space_name() end
>>   tmp = nil
>> @@ -177,45 +189,53 @@ n_spaces = 0
>>   function get_rnd_acc()
>>       return math.floor(math.random() * n_accs)
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function get_rnd_val()
>>       return math.floor(math.random() * 10)
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function get_rnd_str()
>>       return garbage[math.floor(math.random() * string_max_size)]
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   additional_spaces = { };
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function add_space()
>>       local tmp_space = box.schema.create_space(get_new_space_name())
>>       table.insert(additional_spaces, tmp_space)
>>       tmp_space:create_index('test')
>>       n_spaces = n_spaces + 1
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function add_acc()
>>       s1:insert{n_accs, 0} n_accs = n_accs + 1
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function add_op(n1, n2, v)
>>       s2:insert{n_ops, n1, n2, v}
>>       n_ops = n_ops + 1
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function acc_add(n, v)
>>       s1:update({n}, {{'+', 2, v}, {'=', 3, get_rnd_str()}})
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function do_op(n1, n2, v)
>>       box.begin()
>>       add_op(n1, n2, v)
>> @@ -223,18 +243,21 @@ function do_op(n1, n2, v)
>>       acc_add(n2, -v)
>>       box.commit()
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function do_rand_op()
>>       do_op(get_rnd_acc(), get_rnd_acc(), get_rnd_val())
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function remove_smth()
>>       s3:delete{i3:min()[1]}
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function init()
>>       for i = 1,accounts_start do
>>           add_acc()
>> @@ -243,8 +266,9 @@ function init()
>>           s3:auto_increment{"I hate dentists!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"}
>>       end
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function work_itr()
>>       for j = 1,operation_count do
>>           do_rand_op()
>> @@ -254,8 +278,9 @@ function work_itr()
>>       remove_smth()
>>       add_space()
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function work()
>>       for i = 1,iteration_count do
>>           if not pcall(work_itr) then
>> @@ -265,11 +290,12 @@ function work()
>>       end
>>       workers_done = workers_done + 1
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   snaps_done = false;
>> ----
>> -...
>> + | ---
>> + | ...
>>   function snaps()
>>       while (workers_done ~= workers_count) do
>>           pcall(box.snapshot)
>> @@ -277,55 +303,63 @@ function snaps()
>>       end
>>       snaps_done = true
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   function wait()
>>       while (not snaps_done) do
>>           fiber.sleep(0.01)
>>       end
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   init();
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   log.info('Part I: creating snapshot start');
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   for i = 1,workers_count do
>>       fiber.create(work)
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>>   local tmp_fib = fiber.create(snaps);
>> ----
>> -...
>> + | ---
>> + | ...
>>   wait();
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   log.info('Part I: creating snapshot done');
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   #s1:select{};
>> ----
>> -- 645
>> -...
>> + | ---
>> + | - 645
>> + | ...
>>   #s2:select{};
>> ----
>> -- 5120
>> -...
>> + | ---
>> + | - 5120
>> + | ...
>> +
>>   s1:drop();
>> ----
>> -...
>> + | ---
>> + | ...
>>   s2:drop();
>> ----
>> -...
>> + | ---
>> + | ...
>>   for k,v in pairs(additional_spaces) do v:drop() end;
>> ----
>> -...
>> + | ---
>> + | ...
>>   s1 = nil s2 = nil additional_spaces = nil;
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   script_code = [[
>>   fio = require'fio'
>>   new_snap_dir = "]] .. fio.pathjoin(box.cfg.memtx_dir, "snap_test") .. [["
>> @@ -358,28 +392,29 @@ log.info('success: snapshot is ok')
>>   os.execute("rm -r " .. new_snap_dir)
>>   os.exit(0)
>>   ]];
>> ----
>> -...
>> + | ---
>> + | ...
>>   script = fio.open(script_path, open_flags, tonumber('0777', 8))
>>   script:write(script_code)
>>   script:close()
>>   
>>   log.info('Part II: checking snapshot start');
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   snaps = fio.glob(snap_search_wildcard);
>> ----
>> -...
>> + | ---
>> + | ...
>>   snaps_find_status = #snaps <= initial_snap_count and 'where are my snapshots?' or 'snaps found';
>> ----
>> -...
>> + | ---
>> + | ...
>>   snaps_find_status;
>> ----
>> -- snaps found
>> -...
>> + | ---
>> + | - snaps found
>> + | ...
>>   snapshot_check_failed = false
>>   while #snaps > initial_snap_count do
>> -    if not snapshot_check_failed and os.execute(cmd) ~= 0 then
>> +    if not snapshot_check_failed and os.execute(cmd) == nil then
>>           snapshot_check_failed = true
>>       end
>>       max_snap = nil
>> @@ -398,16 +433,20 @@ while #snaps > initial_snap_count do
>>       fio.unlink(max_vylog)
>>       snaps[max_snap_k] = nil
>>   end;
>> ----
>> -...
>> + | ---
>> + | ...
>>   snapshot_check_failed;
>> ----
>> -- false
>> -...
>> + | ---
>> + | - false
>> + | ...
>> +
>>   log.info('Part II: checking snapshot done');
>> ----
>> -...
>> + | ---
>> + | ...
>> +
>>   test_run:cmd("setopt delimiter ''");
>> ----
>> -- true
>> -...
>> + | ---
>> + | - true
>> + | ...
>> +
>> +
>> diff --git a/test/wal_off/snapshot_stress.test.lua b/test/wal_off/snapshot_stress.test.lua
>> index 34b3e7b78..715da9eca 100644
>> --- a/test/wal_off/snapshot_stress.test.lua
>> +++ b/test/wal_off/snapshot_stress.test.lua
>> @@ -40,7 +40,7 @@ script = fio.open(script_path, open_flags, tonumber('0777', 8))
>>   script:write("os.exit(0)")
>>   script:close()
>>   res = os.execute(cmd)
>> -str_res = 'precheck ' .. (res == 0 and ' ok(2)' or 'failed(2)')
>> +str_res = 'precheck ' .. (res == true and ' ok(2)' or 'failed(2)')
>>   str_res
>>   
>>   snap_search_wildcard = fio.pathjoin(box.cfg.memtx_dir, '*.snap');
>> @@ -237,7 +237,7 @@ snaps_find_status = #snaps <= initial_snap_count and 'where are my snapshots?' o
>>   snaps_find_status;
>>   snapshot_check_failed = false
>>   while #snaps > initial_snap_count do
>> -    if not snapshot_check_failed and os.execute(cmd) ~= 0 then
>> +    if not snapshot_check_failed and os.execute(cmd) == nil then
>>           snapshot_check_failed = true
>>       end
>>       max_snap = nil
>> -- 
>> 2.20.1 (Apple Git-117)
>>