[tex-k] another note from Knuth

[Maggie McLoughlin]

Dear TeX-Kers,

Today I have good news for you!

Having installed the current texlive-full package on my new computer,
I needed to run the new MetaPost to create more than 1300 illustrations
that had been used in TAOCP. Since MetaPost was significantly upgraded by
a new team, I was naturally worried that there would be incompatibilities.

Sure enough, 165 of the figures now have slightly different bounding boxes
than before (with the obvious potential of changing page breaks and line breaks).

I tracked the differences down to the fact that the new MetaPost fixes a
bug in the old: The "fill <contour> withpen <pen>" command used to forget
to take the width of the pen into account when adjusting the bbox
(although "draw <path> withpen <pen>" did not forget). As a result,
I got a small discrepancy whenever I used "drawdot" at the edge of
an illustration.

All 165 of the changed figures fell into this category. But of course
I can't complain, because MetaPost now works correctly at last.

The changed illustrations meant that I had to change the manuscript
for TAOCP in four places (pages 61, 222, 227, and 228 of Volume 3)
in order to avoid bad page breaks. So my worries were well founded;
tiny changes to spacing can indeed have drastic consequences.

But thank goodness all those pages now look good again, and TAOCP
has weathered the transition to texlive.

Thanks for good work. -- Don