Re: [Bug] "You can't edit this part of the Custom buffer"

[Chong Yidong]

>     Why was this change made in the first place?  It seems
>     pointless---Custom buffers are read-only, so self-insertion commands
>     do nothing anyway; we don't have to bind them to a 'custom-no-edit'
>     command that does nothing but raise an error.
>     
> I'm not responsible for the fix, but I reported the bug that was
> fixed: See the thread "Customize buffer modification: indicator,
> feedback, undo" in emacs-pretest, of June 10-11, 2006.

>From your bug report:

    2. Trying to type in the header text has no effect. There should be a
       message indicating that that area of text is read-only. Otherwise,
       with no feedback, the user doesn't understand what's happening and
       why.

I think this is an unreasonable quibble.

With the old behavior, when you try to insert something in a Customize
buffer, you get an error:

  "Text is read-only: Attempt to change text outside editable field"

Now, you get the error:

  "You can't edit this part of the Custom buffer"

The difference is negligible.  No user is going to get confused about
why they can't edit the Customize buffer---it's obvious, from the
appearance of the buffer, which contains buttons and hyperlinks, that
it's not meant to be edited.  (In a similar vein, we don't worry that
users will type "s" in an Info buffer and be shocked that it runs
Info-search instead of inserting text!)