bug#1120: issues on (put 'insert-date 'delete-selection t)

[Richard M. Stallman]

    For elisp programers who wish to write extentions where the command's  
    behaviors change depending on whether user has delete-selection-mode  
    on, what should they do? Check for mark-active and delete-selection- 
    mode before any call to the insert function?

If you really want to make behavior depend on those variables,
you need to check them.  Whether you check them before or after
calling `insert' is up to you.

But that seems like a strange thing to do.