Subject: bug#19622: 25.0.50; Spell checking and Unicode don't mix...

From: Eli Zaretskii <[email-masked]>
Date: Mon, 19 Jan 2015 05:35:18 +0200

> Date: Sat, 17 Jan 2015 20:55:33 -0500
> From: "Perry E. Metzger" <[email-masked]>
> 
> 
> Say you're using a mode (like typopunct) which automatically inserts
> "proper" Unicode close single quote marks while you're typing. You
> then would spell "hadn't" as "hadn’t", say.
> 
> Say you're also using flyspell mode (or even normal ispell checks).
> 
> "hadn’t" will then be flagged as misspelled, mostly because none of
> the tools seem to understand that "’" is the same as "'" under the
> circumstances.
> 
> It would be really handy if the spell checker was happy with either.

It's up to the speller, so it isn't an Emacs problem/bug/issue.  The
characters that are word constituent are stated in the .aff file for
the language you use, and they come with the speller (and are tailored
to what the speller does and doesn't know about the word structure).
Emacs cannot fix that.