Re: Run coding system auto-detection manually?

[Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann)]

Richard Stallman <rms@gnu.org> writes:

>     When the file is precious, Emacs already writes to a different file
>     first and then renames the file.  Therefore, the spot where Emacs
>     invokes write-region if the file is precious must already take care
>     of this.  At that spot, (the function called from) save-buffer just
>     passes the real file name as the LOCKNAME argument.
>
> I don't think write-region looks at the LOCKNAME argument in
> deciding which coding system to use.  I think it looks only at
> the FILENAME argument.
>
> Handa, do you think it looks at LOCKNAME?
>
> Is this a bug in the handling of coding systems for precious files?

I'm sorry, I confused LOCKNAME and VISIT.  After looking again in
basic-save-buffer-2, I see the following call:

		       (write-region (point-min) (point-max)
				     tempname nil realname
				     buffer-file-truename)

This is in the "precious" case.  So you can see that the real
filename is in the VISIT argument, not in the LOCKNAME argument.  I
got those two confused before.

Presumably, the intent was that write-region choose the coding system
based on realname instead of tempname.

But looking in the code for write-region, I don't find any evidence
that it looks at VISIT, only at FILENAME, for detecting the coding
system.  Hm.

Maybe in the above call, tempname has been devised in such a way that
choose_write_coding_system chooses the "right" coding.

I'm somewhat confused at the moment.  Can somebody clear up the
confusion?  Is there a bug (regarding VISIT instead of LOCKNAME), as
Richard suggests?  Or does the code work right?

kai
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