bug#14943: 24.3.50; Now just making text invisible locks the file for editing

[Drew Adams <drew.adams@oracle.com>]

emacs -Q

Visit a file and make some text invisible, e.g., using C-S-mouse-2 > 
Special Properties > Invisible.  That's all.

emacs -Q ; another session.

Visit the same file and try to make some other text invisible.

You get this (nearly incomprehensible) prompt:

"...part-of-name.el locked by dradams@DRADA... (pid 6928): (s, q, p, ?)? "

When is Emacs going to stop treating operations like changing text
properties the same way it treats normal edits that would affect the
file if saved?  This is silly.  There is buffer modification and buffer
modification.  This kind of modification - changing text properties - is
not something we should be locking a file for and warning users about.

And then if you can actually figure out that to be able to figure out
the message/prompt you can hit `?' for help, and if you do that, you get
this lovely explanation:

  It has been detected that you want to modify a file that someone else
  has already started modifying in Emacs.

  You can <s>teal the file; the other user becomes the
    intruder if (s)he erver unmodifies the file and then changes it again.
  You can <p>roceed; you edit at your own (and the other user's) risk.
  You can <q>uit; don't modify this file.

I don't even know what to say about how bad that is.

And FWIW I typed it all in - it does not get logged to *Messages* and I
didn't realize it was available in *Help* after I tried to click it to
select it and *Help* disappeared!  This is what happened when I clicked
*Help* (only the second msg appeared in the echo area; both messages are
taken from *Messages*):

ask-user-about-lock: Non-character input-event
mouse-minibuffer-check: Wrong type argument: window-valid-p, #<window 04f6b1b8>

Pretty bad, Emacs.  You can do much better.


In GNU Emacs 24.3.50.1 (i686-pc-mingw32)
 of 2013-07-14 on ODIEONE
Bzr revision: 113423 lekktu@gmail.com-20130715004922-i67tg2ois14h3fpm
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/binary --enable-checking=yes,glyphs
 CFLAGS='-O0 -g3' CPPFLAGS='-Ic:/Devel/emacs/include'
 LDFLAGS='-Lc:/Devel/emacs/lib''