Hello, Sergey,

thanks for the patch! See comments below.


On 19.12.2024 12:30, Sergey Kaplun wrote:
> The `strtod parsing` subtest in the <lib/base/tonumber_scan.lua> checks
> the results yielded by the `strtod()` via FFI call. In glibc versions
> before 2.28 it returns an incorrect result (NaN instead of inf) for
> "0x3p1023" [1]. This patch hardens the skipcond for this test for a
> smaller version of the libc installed.
>
> [1]:https://sourceware.org/bugzilla/show_bug.cgi?id=23279
> ---
>
> Branch:https://github.com/tarantool/luajit/tree/skaplun/gh-noticket-fix-glibc-versions
>
> The CI failure for libc 2.23 (ubuntu 16):
> https://github.com/tarantool/tarantool/actions/runs/12376159316/job/34542626889?pr=10949#step:5:13916
Ubuntu 16.04 EOL and EOS are reached [1]
> The CI failure for libc 2.24 (debian 9):
> https://github.com/tarantool/tarantool/actions/runs/12376159307/job/34542633454?pr=10949#step:5:13859
Debian 9 EOL is reached 4 years ago [2]
> The CI failure for libc 2.27 (ubuntu 18):
> https://github.com/tarantool/tarantool/actions/runs/12376159278/job/34542625496?pr=10949#step:5:11743
> The CI pass for libc 2.31 (ubuntu 20):
> https://github.com/tarantool/tarantool/actions/runs/12376159289/job/34542630993?pr=10949
Ubuntu 20.04 support ends in 3 months and 2 week [1].


>
>   test/LuaJIT-tests/lib/base/tonumber_scan.lua | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/test/LuaJIT-tests/lib/base/tonumber_scan.lua b/test/LuaJIT-tests/lib/base/tonumber_scan.lua
> index ac7d68a4..800c57b0 100644
> --- a/test/LuaJIT-tests/lib/base/tonumber_scan.lua
> +++ b/test/LuaJIT-tests/lib/base/tonumber_scan.lua
> @@ -186,9 +186,11 @@ do --- tonumber parsing
>     test_conv(tonumber)
>   end
>   
> --- Skip for the old libc version with the bug in the `strtod()`.
> --- See alsohttps://sourceware.org/bugzilla/show_bug.cgi?id=16151.
> -do --- strtod parsing -libc<2.19
> +-- Skip for the old libc version with the bugs in the `strtod()`.
> +-- Affected versions:
> +-- * <2.19:https://sourceware.org/bugzilla/show_bug.cgi?id=16151.
> +-- * <2.28:https://sourceware.org/bugzilla/show_bug.cgi?id=23279.

I propose to skip strtod test when Glibc is older than say 2.30 [3] and 
avoid testing

with ancient Glibc versions because Glibc implementation is buggy [4] and

a there are lot of bugs in old and more or less new versions:

v2.41 [5], v2.22 [6], v2.27 [7], v2.15 [8], v2.33 [9] etc [10].


I don't think we should waste our time with issues like this.


1. https://endoflife.date/ubuntu

2. https://endoflife.date/debian

3. https://sourceware.org/glibc/wiki/Release

4. 
https://github.com/tarantool/luajit/blob/cd5ab5da9b56bf560407554c0377cfa8567d4430/src/lj_strscan.c#L20-L27

5. https://sourceware.org/bugzilla/show_bug.cgi?id=30220

6. https://sourceware.org/bugzilla/show_bug.cgi?id=19380

7. https://sourceware.org/bugzilla/show_bug.cgi?id=15744

8. https://sourceware.org/bugzilla/show_bug.cgi?id=14049

9. https://sourceware.org/bugzilla/show_bug.cgi?id=26137

10. 
https://sourceware.org/bugzilla/buglist.cgi?bug_status=__all__&content=strtod&no_redirect=1&order=bug_id%20DESC&product=glibc&query_format=specific

> +do --- strtod parsing -libc<2.28
>     test_conv(function(s)
>       local d = ffi.C.strtod(s, e)
>       return (e[0][0] == 0 and #s ~= 0) and d or nil