intangible characters bugs [was Re: buff-menu.el changes]

["Robert J. Chassell" <bob@rattlesnake.com>]

Today's CVS snapshot of Tue, 2002 Dec 17 16:51 UTC
GNU Emacs 21.3.50.27 (i686-pc-linux-gnu, X toolkit)
(but with Miles' patch to src/xfaces.c applied to that file)
started with

     /usr/local/bin/emacs -q --no-site-file --eval '(blink-cursor-mode 0)'


   next-line (C-n) works for me, even with 21.2 -q.  It simply skips
   the intangible line.

This is a bug in 21.3.  Miles Bader <miles@lsi.nec.co.jp> sent a
test-case.  I can confirm that the current CVS snapshot has the same
problems as he describes.  I cannot fix this.


    ... here's a simple test-case that illustrates the
    problem:

       (with-current-buffer (get-buffer-create "*test*")
         (insert "1: hello\n")
         (insert (propertize "2: cruel\n" 'invisible t 'intangible t))
         (insert "3: world\n")
         (insert "4:\n"))

    After evaluating that, go to the *test* buffer, and move around
    using C-n & C-p.  I can see the following bugs:

      (1) If the cursor is in the first column, you can't move from
          line "3:" to line "4:" using C-n (but C-p works all the way
          from the end of the buffer to the beginning).

      (2) If the cursor is in a different column, C-n seems to work
          correctly on all lines, but C-p won't move from line "3:" to
          line "1:" (it seems to work on all other line though).

-- 
    Robert J. Chassell                         Rattlesnake Enterprises
    http://www.rattlesnake.com                  GnuPG Key ID: 004B4AC8
    http://www.teak.cc                             bob@rattlesnake.com