In my revamp of cursor handling I had assumed that you were supposed

In my revamp of cursor handling I had assumed that you were supposed
to call _either_ do_text() _or_ do_cursor() on a given character
cell. In fact you're supposed to call do_text() no matter what, and
then call do_cursor() as well if it's got the cursor on it, since
do_cursor() _only_ draws the actual cursor, which often doesn't also
cause the text to get drawn.

I'm half tempted to change this in the interface, retire do_cursor()
as an external function and relegate it to an internal function in
each front end, and require that do_text() must fully process all
cursor attributes it is passed. However, I haven't done this yet.

[originally from svn r5017]