It does not seem to be standard practice for Tk-based interfaces (and
indeed it was not part of GraphApp on Windows -- I added it after some
years).
If you supply a tested patch to the R-devel sources it will be considered
for 2.8.0. The 'next version' is 2.7.2 and imminent, so I don't think
Am I the only one who finds himself futilely double-clicking a CRAN
mirror in the dialog for choosing a CRAN mirror? Yes, double-clicking
works in Windows, but not in the Tk-based dialog on Linux. I'm going
to wear out my mouse button.
Adding the following line to the tk_select.list function in th