Handling of duplicate entries when choosing columns from the students file (Feature #83)
In the choice of the column containing the identification of the
students, auto-multiple-choice only offers those columns that contain
no duplicate. This is a sane safety feature. However I was not aware
of it and I spent a good deal of time wondering why my column did not
appear. It's only by dichotomy on the file that I finally figured out
that my file was broken with two students having the same id.
I would suggest instead to display all columns; and then, once one of
them is selected, to pop up if needed an error like ``column xxx
contains a duplicate id: xxx''.