Subject: Re: bug#76382: 29.4; TeX Input Mode

From: Eli Zaretskii <[email-masked]>
Date: Tue, 18 Feb 2025 19:19:58 +0200

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> From: Ben Domine <[email-masked]>
> Date: Tue, 18 Feb 2025 10:12:46 -0600
> 
> Of course:
> 1. emacs -Q
> 2. C-x RET C-\
> 3. tex RET
> 4. ^C (shift-6 shift-c, on my keyboard)
> 
> Expected result is a superscript capital C. Here are the equivalent superscripts for lowercase c and capital
> D: ᶜ ᴰ
> 
> This might very well just be a native font issue, or it could be that emacs is trying to insert the wrong
> character (I’m not sure which).

Do you have a font installed which supports the codepoint U+A7F2?  If
I arrange for such a font to be available to Emacs, the results are as
you expect.

But the problem as you originally described was different:

> I turned on TeX input mode and attempted to write the exponentiated
> capital C. In the minibuffer this is displayed as an option, however
> when I type it I get the unknown character symbol.

If by "In the minibuffer this is displayed as an option" you mean that
"C" was one of the alternatives shown after "^", then the fact that
this alternative is shown does not mean you have a font that can
display that alternative.  The input method does not check whether
such a font is available, and it shouldn't check that: you are
supposed to be able to type a character even if Emacs on your system
cannot display it, because it could be displayable on another system,
or even on yours after you install the missing fonts.

So I don't think there's a bug in Emacs here.  You need to install
some additional fonts, and then it should work as expected.