[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Risky local variable mechanism
From: |
Luc Teirlinck |
Subject: |
Re: Risky local variable mechanism |
Date: |
Tue, 7 Feb 2006 23:00:11 -0600 (CST) |
Chong Yidong wrote:
Er, it is always safe to *add* to a list of local variables to ignore.
Not if you do it _through Custom_. You did not understand what I wrote
in my first message. After the release, we introduce some new variable so
dangerous that it _has_ to be in `ignored-local-variables'. We add
that variable to the standard value in the defcustom. Now anybody who
customized `ignored-local-variables' in the meantime will _not_ get
that dangerous variable added to `ignored-local-variables'. This is
an updating problem.
The safe way to add to `ignored-local-variable' is using add-to-list,
not using setq. Your code uses add-to-list *when it is called*, but
after that, it lets Custom do the work and Custom uses set-default,
which is not safe.
The same type of updating problem also occurs for `safe-local-variables'.
As Stefan pointed out, there is also another type of updating problem
with `safe-local-variables', because a safe variable can become unsafe
if it gets changed to be more powerful. This type can combine with
the other. If we add a variable to the standard value in one release
and then have to remove it in a later release from some reason, then
anybody who customized the variable _through Custom_ will not get that
variable removed from his customized value. Somebody who only used
add-to-list to add other variables, will get it properly removed.
Sincerely,
Luc.
- Re: Risky local variable mechanism, (continued)
- Re: Risky local variable mechanism, Luc Teirlinck, 2006/02/06
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/07
- Re: Risky local variable mechanism, Luc Teirlinck, 2006/02/07
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/07
- Re: Risky local variable mechanism, Luc Teirlinck, 2006/02/07
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/07
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/07
- Re: Risky local variable mechanism, Luc Teirlinck, 2006/02/08
- Re: Risky local variable mechanism,
Luc Teirlinck <=
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/08
- Re: Risky local variable mechanism, Stefan Monnier, 2006/02/07
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/07
- Re: Risky local variable mechanism, Stefan Monnier, 2006/02/08
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/08
- Re: Risky local variable mechanism, Stefan Monnier, 2006/02/08
- Re: Risky local variable mechanism, Chong Yidong, 2006/02/08
- Re: Risky local variable mechanism, Stefan Monnier, 2006/02/08
- Re: Risky local variable mechanism, Luc Teirlinck, 2006/02/08
- Re: Risky local variable mechanism, Stefan Monnier, 2006/02/08