Re: xml-parse-file and text properties

[Richard Stallman]

    ??? Composition is just a text property.  It doesn't change
    the character sequence.  It just changes how characters are
    displayed.

If it replaces two characters with one character, that makes
a difference what the text is.  You've said that users would
perceive them as different characters.

Does the composition property affect the sequence of characters that
would be written to a file?  I have a vague memory that it does.

    In emacs-unicode-2, loosing of composition property has no
    problem because I've implemented a code to construct
    composition automatically in display engine.

That definitely seems like an improvement; could you tell me more?
However, at present, we need to make the right things happen in Emacs
22.

    > 1. Distinguish composition properties from others, and make functions
    > like buffer-substring-no-properties preserve composition properties,
    > even as they discard all other properties.

    > Can #1 work?

    I don't know.  If text properties causes a problem in XML,
    #1 doesn't solve the current problem.  If text properties is
    not a problem, we don't need #1.

He said that the text properties in XML cause a serious problem when
they are numerous.  Keeping all is no good; discarding all text
properties would be wrong when there is a composition property.
However, keeping just the composition property would be fine, since
most of the time there won't be any of them.

However, the problem of losing composition properties is not limited
to XML.