Re: Emacs opens only first 16384 bytes of file?!

[Ruijie Yu via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Christoph Groth <christoph@grothesque.org> writes:

> Hello,
>
> I just noticed something that made me doubt my own sanity:  With Emacs
> 27.1 (from Debian stable running Debian’s Linux kernel
> 6.0.0-0.deb11.6-amd64) the command
>
>   emacs -q -nw /proc/cpuinfo
>
> reproducibly opens cpuinfo only up to a portion of line 272, while the
> entire file is 560 lines long on that machine.  I checked on a different
> machine (with same Emacs), and I see the same behavior.
>
> C-u C-x = tells that the file is read up to position 16384 (= 2^14).

Can't reproduce on 28.1 nor 29 (8a18369afdc3).  Can you compile 28.1 and
see if the problem goes away?

Since my /proc/cpuinfo is smaller than 16384 bytes, I used the following
steps to try to reproduce the issue:

$ zcat /proc/config.gz > ~/c
$ /path/to/emacs-28.1/src/emacs -Q -nw ~/c
`C-u C-x =' says: "position: 1 of 252720 (0%), column: 0"

> Running M-x revert-buffer loads the whole file...
>
> Is/was this a known issue?  I could not find anything on the web.

In the future you might get more responses if you mail to
bug-gnu-emacs@gnu.org.

> ----------------------------------------------------------------
>
> I’m willing to investigate this further, but it would seem very strange
> if Emacs indeed had a bug that prevented it from loading some files
> entirely.  Perhaps someone here knows the answer.
>
> Thanks
> Christoph

--
Best,


RY