[Tarantool-patches] [PATCH luajit 1/2] Fix corner case of os.time().

[Sergey Kaplun]

Hi, Evgeniy!
Thanks for the patch!
LGTM, with minor nits below.

On 29.06.26, Evgeniy Temirgaleev wrote:
> From: Mike Pall <mike>
> 
> Thanks to Temir Galeev. #1470

Please strip the issue number to avoid overmentioning the ticket on
GitHub. (The Issue can be easily found by the cherry-picked commit,
though). This helps to avoid overmentioning during the review and
applying the patch to long-term branches.

> 
> (cherry picked from commit 72d2061ae2fa9a5fd45237943f9982baf59435ec)
> 
> This patch fixes invalid os.time(t) behavior, when it handles -1 time value

Typo: s/, when/ when/
Typo: s/-1/the -1/

> as a fail of the libc mktime() regardless of the errno value.
> 
> Temir Galeev:
> * added the description and the test for the patch
> 
> Part of tarantool/tarantool#12480
> ---
>  src/lib_os.c                                         |  3 ++-
>  .../lj-1470-os-time-epoch-minus-1s.test.lua          | 12 ++++++++++++
>  2 files changed, 14 insertions(+), 1 deletion(-)
>  create mode 100644 test/tarantool-tests/lj-1470-os-time-epoch-minus-1s.test.lua
> 
> diff --git a/src/lib_os.c b/src/lib_os.c
> index ffbc3fdc..f6841357 100644
> --- a/src/lib_os.c
> +++ b/src/lib_os.c
> @@ -242,9 +242,10 @@ LJLIB_CF(os_time)
>      ts.tm_mon = getfield(L, "month", -1) - 1;
>      ts.tm_year = getfield(L, "year", -1) - 1900;
>      ts.tm_isdst = getboolfield(L, "isdst");
> +    errno = 0;
>      t = mktime(&ts);
>    }
> -  if (t == (time_t)(-1))
> +  if (t == (time_t)(-1) && errno != 0)
>      lua_pushnil(L);
>    else
>      lua_pushnumber(L, (lua_Number)t);
> diff --git a/test/tarantool-tests/lj-1470-os-time-epoch-minus-1s.test.lua b/test/tarantool-tests/lj-1470-os-time-epoch-minus-1s.test.lua
> new file mode 100644
> index 00000000..6b5703e4
> --- /dev/null
> +++ b/test/tarantool-tests/lj-1470-os-time-epoch-minus-1s.test.lua
> @@ -0,0 +1,12 @@
> +local tap = require('tap')
> +
> +-- The test file demonstrates os.time() fail to return -1 time value.

Side note: It looks like the patch is outdated compared to the branch.

> +-- See also: https://github.com/LuaJIT/LuaJIT/issues/1470.
> +local test = tap.test('lj-1470-os-time-epoch-minus-1s')
> +
> +test:plan(1)
> +
> +local minus_1s_time = os.date("*t", -1)

Nit: We use everywhere in Lua code single quotes if possible (see other
tests).

> +test:is(os.time(minus_1s_time), -1, 'correct os.time()')
> +
> +test:done(true)
> -- 
> 2.49.0
> 

-- 
Best regards,
Sergey Kaplun