I've long been aware that GPLv2 "technically" governed private
modifications and that generally there were probably more requirements
on privately modified versions of GPLv2'd works than most people assumed
in practice, including commonly held public interpretation by FSF.
HT Wolvereness, who pointed out to me that GPLv3 solved that problem.
When I spoke to Fontana about it, he was indeed aware that this text was
"missing" in GPLv2 and that GPLv3 properly added it, through some
politics during the GPLv3 process.
I've added herein the ultimate historical conclusions about GPLv2's
interpretation and how GPLv3 clarified it. I've left out the color
about the politics of how it got added, not because they are not
interesting, relevant and germane to tutorial, but because we don't have
a good place yet in the tutorial for discussion of GPLv3 drafting
politics, and frankly if we have such a section, Fontana ought to write
it, not me.
This text needs to be clear that GPLv2§2 doesn't govern merely the act
of modification, but distributing modified versions (in whole or in
part). The previous text here wasn't clear on that point.
While both GPLv2 and GPLv3 have long been considered to grant unabridged
right to private modification, GPLv3 has much clearer and explicit
wording to this effect.
This should be noted when that paragraph is explained. This change
herein does that.
HT Wolvereness for pointing this difference between GPLv2 and GPLv3 out
to me.