bug#51011: [GNU sort] Numerical sort with delimiter may be broken (bug)

[Juncheng Yang]

Thank you, Paul and Padraig! 
May I ask when it fails to sort numerically why 1,a comes before 0,9? I could 
not come up with an ordering that 1,a is smaller. 


Best, 
Jason 


> On Oct 4, 2021, at 4:01 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
> 
> On 10/4/21 08:58, Pádraig Brady wrote:
>> The --debug option points out the issue:
>>   $ printf '%s\n' 1,a 0,9 | sort --debug -nk1 -t ,
>>   sort: key 1 is numeric and spans multiple fields
>>   1,a
>>   _
>>   ___
>>   0,9
>>   ___
>>   ___
> 
> As Juncheng points out, it is a bit odd that -n and -g disagree here, even in 
> locales where ',' is not a decimal point. For example:
> 
> $ printf '1,a\n0,9\n' | sort -gk1 -t, --debug
> sort: text ordering performed using ‘en_US.UTF-8’ sorting rules
> sort: key 1 is numeric and spans multiple fields
> 0,9
> _
> ___
> 1,a
> _
> ___
> $ printf '1,a\n0,9\n' | sort -nk1 -t, --debug
> sort: text ordering performed using ‘en_US.UTF-8’ sorting rules
> sort: key 1 is numeric and spans multiple fields
> 1,a
> _
> ___
> 0,9
> ___
> ___