separator omitted when first argument is null or empty

[rrs]

consider the template <["Wendy",,"Jane"]; separator=",", null=""> it will print Wendy,,Jane however the template <[,"Wendy","Jane"]; separator=",", null=""> will print Wendy,Jane and not ,Wendy,Jane

This is an issue for a template i have that builds a csv output, when the first column happens to contain null values. A work around is to use null=" " however that means there would be no distinction between "" and " "

Further to that if i have a dictionary i wish to print in a line and use <d.keys:{k | <d.(k)>}; separator=",", null=" "> then there is nothing i can do to keep the leading comma as the dictionary lookup resolves to "" even if the value is null and therefore doesn't count towards the null replacement.