Re: How does one disable (UTF-8?) input "fixup"?

[Eli Zaretskii]

> From: Winston <wbe@UBEBLOCK.psr.com.invalid>
> Date: Mon, 11 Jan 2016 05:16:13 -0500
> 
> What mode/variable controls text conversion/fixup when reading a file?
> 
> I have a mostly ASCII text file that contains a few stray non-ASCII
> characters.

You need to prefix "C-x C-f" with "C-x RET c us-ascii RET".  See the
node "Text Coding" in the Emacs manual.

Or use "M-x find-file-literally" to disable any conversions.

> However, if I rename the file "foo.exe", do "emacs foo.exe" and search,
> I see the original characters (no change).

Emacs by default visits binary files without any conversions.

> Curiously, after "emacs foo.exe", I did find-file-other-window to read
> in "foo", and the characters were NOT altered.

Because the file is already in an Emacs buffer, so Emacs doesn't
re-read it, it just reuses that buffer's contents.

> What controls whether that conversion is done or not?  Is there an easy
> way to turn it on/off?  I didn't see anything in the results from
> apropos "-mode" that looked relevant.

Text decoding is not a mode, it is a basic feature of any I/O Emacs
does.