[Tarantool-patches] [PATCH] box/console: Fix crash in error message

[Alexander Turenko]

The patch LGTM. I made minor changes (listed below) and pushed the patch
to master and 2.2 (CCed Kirill).

Thanks!

WBR, Alexander Turenko.

On Fri, Nov 08, 2019 at 04:54:16PM +0300, Cyrill Gorcunov wrote:
> The former message has been dropped by tarantool.org receivers,
> so lets try to resend...
> ---
> box/console: Fix crash in error message
> When invalid command passed we should print out
> the excat value, instead due to typo in
> 96dbc49d097a96af5273cce2b5663db5917f4ea9 we
> cause a nil dereference.

I rewrote the message a bit:

 | box/console: fix abnormal exit after unknown command
 |
 | When invalid command is passed we should send an error message to a
 | client. Instead a nil dereference occurs that causes abnormal exit of a
 | console.
 |
 | This is the regression from 96dbc49d097a96af5273cce2b5663db5917f4ea9
 | ('box/console: Refactor command handling').
 |
 | Reported-by: Mergen Imeev <imeevma at tarantool.org>
 | Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>
 | Reviewed-by: Alexander Turenko <alexander.turenko at tarantool.org>

> Reported-by: Mergen Imeev <imeevma at tarantool.org>
> Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>
> ---
>  src/box/lua/console.lua | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
> index 52df67465..d4d8ec984 100644
> --- a/src/box/lua/console.lua
> +++ b/src/box/lua/console.lua
> @@ -323,7 +323,7 @@ local function preprocess(storage, line)
>      end
>      if items == nil then
>          local msg = "Invalid command \\%s. Type \\help for help."
> -        return format(false, msg:format(items[1]))
> +        return format(false, msg:format(line))
>      end
>      return operators[items[1]](storage, unpack(items))
>  end
> -- 
> 2.20.1
> 

Added the test case:

 | diff --git a/test/app-tap/console.test.lua b/test/app-tap/console.test.lua
 | index 9e8b41b84..d9db5f887 100755
 | --- a/test/app-tap/console.test.lua
 | +++ b/test/app-tap/console.test.lua
 | @@ -21,7 +21,7 @@ local EOL = "\n...\n"
 |  
 |  test = tap.test("console")
 |  
 | -test:plan(72)
 | +test:plan(73)
 |  
 |  -- Start console and connect to it
 |  local server = console.listen(CONSOLE_SOCKET)
 | @@ -292,6 +292,19 @@ client:write("box.session.type();\n")
 |  test:is(yaml.decode(client:read(EOL))[1], "console", "session type")
 |  client:close()
 |  
 | +--
 | +-- An unknown backslash started command causes abnormal exit of
 | +-- a console.
 | +--
 | +local cmd = '\\unknown_command'
 | +local exp_res = {error = string.format(
 | +    'Invalid command %s. Type \\help for help.', cmd)}
 | +client = socket.tcp_connect("unix/", CONSOLE_SOCKET)
 | +client:read(128)
 | +client:write(('%s\n'):format(cmd))
 | +local res = yaml.decode(client:read(EOL))[1]
 | +test:is_deeply(res, exp_res, 'unknown command')
 | +client:close()
 | +
 |  server:close()
 |  
 |  box.schema.user.drop('test')