Re: [Bug-AUCTeX] Re: preview-1.248; preview completely broken?

[David Kastrup]

address@hidden (R.P.I. Lewis) writes:

> David Kastrup <address@hidden> writes:
>
>>> with debug-on-signal the first backtrace produced is:
>>>
>>> Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
>>>   coding-system-plist(nil)
>>>   coding-system-get(nil alias-coding-systems)
>>>   coding-system-base(nil)
>>>   byte-code("..
>>
>> Oops, that looks bad.  It means that buffer-file-coding-system for
>> the buffer from which you started preview-latex is _nil_.  Is this
>> the same for default-buffer-file-coding-system on your system as
>> well?
>>
>> C-h v default-buffer-file-coding-system RET
>
> default-buffer-file-coding-system's value is nil
>
> C-h C RET says
>
> Coding system for saving this buffer:
>   Not set locally, use the default.
> Default coding system (for new files):
>   nil
> Coding system for keyboard input:
>   nil
> Coding system for terminal output:
>   nil
> Defaults for subprocess I/O:
>   decoding: - -- undecided
>
>   encoding: 1 -- iso-latin-1 (alias: iso-8859-1 latin-1)

Great.

>> would give that information.  Do you have any idea how this value
>> comes about?  It would indicate that Emacs can't figure out a buffer
>> encoding for writing the file, namely that your locale settings are so
>> inconsistent as to make Emacs unable to guess a coding system.
>>
>
> I have
>
> $ locale
> LANG=
> LC_CTYPE="C"
> LC_COLLATE="C"
> LC_TIME="C"
> LC_NUMERIC="C"
> LC_MONETARY="C"
> LC_MESSAGES="C"
> LC_ALL=
>
> is that the cause? (and how do i chaange that? export LANG=C and
> export LC_ALL=C dont seem to help)

Wow.  Yes, that would probably be like it.

LANG=en_US

would be a good choice for typical systems, unless your C library does
not support locales at all.  I found that calling "perl" without
arguments is one way to figure out whether a specific locale setting
is supported: perl tends to complain rather loudly if not.

>> Can you write files without Emacs asking for a coding system?
>
> i've never been asked anything (and files save fine)

Presumably if they are ASCII-only, no weird 8bit characters.

I have committed the following fix to preview.el which should help in
your case.

txtnwr_tePlWm.txt
Description: Text Data

Sorry, we foreigners really are not used to systems which don't know
anything about languages, and so this problem crept in.  Please check
whether this cures your problem without you having to change your
locale.  Not that it would be a bad idea to do so, but that's a
different problem.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum