[Groff] PS font metrics change (again)

[Werner LEMBERG]

I have changed the PS font metrics again, using a new switch to
afmtodit (-m, don't allow negative left italic correction values --
internally, afmtodit calls the left italic correction `left math
fit').

The old fonts didn't behave well with eqn -- this preprocessor uses

  \,X\/

(X an arbitrary glyph) almost everywhere to get mathematical spacing.

While reading the source code of eqn I found out that it checks
whether the left and/or right glyph is italic, emitting \, (\/) only
if the previous (next) glyph is roman.  I wonder why.

Consider this:

  $f f$

With TeX, the two (italic) f's are clearly separated, while with eqn
the two glyphs almost touch.

Compare this with

  .ft I
  f\/\,f

and you see what I mean.

I'm going to remove this code since I can't imagine a situation where
this feature is needed.  For inserting real words (and not
single-letter variables) just quote it like this: "ff".


    Werner