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

[Juncheng Yang]

Hi coreutils developers, 
    I have encountered a bug in GNU sort in which sort produces incorrect 
results when numerical sort with delimiters. For example, 
sort -nk1 -t , file 
cannot sort the a file with the following lines (sort by the first column 
numerically) 
1,a
0,9

I have tried multiple version including the latest version, this problem still 
exists. 


Best, 
Juncheng