Re: Emacs text bug

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 31 Jan 2013 11:28:47 -0800 (PST)
> From: drain <aeuster@gmail.com>
> 
> Now I see. This problem must have started when I copied an early 19th
> century letter into the buffer, and the characters did not transliterate
> properly into modern English. Whatever those characters were, they turned
> into circumflexed /a/ (â), the pound sign (£), and a (special) right double
> quotation mark (”). utf-8 apparently cannot handle these.

UTF-8 certainly _can_ handle them.  I suspect that these characters
got copied as raw bytes instead.

> But why would this prevent utf-8 from encoding the rest of the buffer? Why
> not just leave those three characters mangled, and display the rest
> properly? It reverted fine; it just would not stay in utf-8 unless I (1)
> put the instruction at the top of the buffer or (2) deleted those special
> characters. So the functionality appears to be there: Emacs just would not
> accept it as a saved state (absent instruction at the top).

Emacs auto-detects the encoding each time you visit a file, unless
either the file (by the 'coding:' cookie) or you (by using "C-x RET c")
tell it exactly how to decode the file.