Re: Insufficient functionality of yank-excluded-properties

[Richard Stallman]

    The reason is that the `category' text property is copied.
    In this specific case, the category is `help-function-def-button'
    which has a mouse-face property.

This is a hard case to see how to handle correctly.

    A better solution might be for remove-list-of-text-properties
    to remove a `category' text property if that category specifies
    one of the excluded text properties in the list.

That might be the right thing to do.  In addition, perhaps we should
avoid puttin on a `mouse-face' property via `category'.  We could change
the Help mode code to put on the `mouse-face' property separately.
Should we do that?