Re: bug of display-table & make-glyph-code

[Richard Stallman]

    But, then, it seems that the design is broken (or got broken
    because of introduction of multibyte characters).  It grows
    glyph-table one by one.  So, at some point a glyph code is
    simply a character code, but after several calls of
    create-glyph, that same glyph code becomes an index into
    glyph-table, and is displayed differently.

Those codes are meaningless as characters.  They start at 256.
Meaningful Mule characters codes are much larger.

If you were to define thousands of glyph codes, you might get into the
range of meaningful Mule characters.  Then indeed things would break.
So there is a bug, in that this could happen.  But it is not the case
that all use of create-glyph is broken.

I am not sure whether create-glyph is very useful nowadays.
Maybe it is obsolete, due to Mule.  Who still ses it
and why does he use it?

    But, for instance, the return value of (make-glyph-code 256)
    is a simple glyph or not depending on the current length of
    glyph-table.

Code 256 is useful only if you have defined it as an entry in
the glyph table.