bug#25641: 25.1; insert-char function inconsistency

[Stephen Berman <stephen.berman@gmx.net>]

On Tue, 07 Feb 2017 18:08:48 +0200 Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Pablo Mercader Alcántara <programingfrik@gmail.com>
>> Date: Tue, 7 Feb 2017 09:04:01 -0400
>> 
>> Character code properties: customize what to show
>>   old-name: BELL
>>   general-category: Cc (Other, Control)
>> [...]
>> Character code properties: customize what to show
>>   name: BELL
>>   general-category: So (Symbol, Other)
>>   decomposition: (128276) ('🔔')
>> 
>> Its a different character but it also states that I could write it using
>> C-x 8 RET BELL. To me that is an inconsistency, because one of the
>> commands that the help screen showed me was C-x 8 RET BELL and that
>> clearly doesn't work.
>
> It's not an inconsistency: the first one has BELL as its "old name"
> property (and has no "name" property), the second one as its "name"
> property.  This is per Unicode definitions in their character
> database, which Emacs uses for this feature.  Unicode removed the
> names of low control characters in some version of their standard,
> leaving the "old name" behind for compatibility.
>
> Emacs displays "old name" if "name" is missing.
>
> If you type "C-x 8 RET BELL" and hit TAB right after that, Emacs will
> tell you this is "complete, but not unique".  Another TAB will pop up
> the list of completion candidates, where you will see both BELLs (and
> a couple more characters).
>
> I don't think there's a bug here.

But as the OP noted, the *Help* buffer for the character #x7 says:

             to input: type "C-x 8 RET 7" or "C-x 8 RET BELL"

yet hitting RET after `C-x RET BELL' only inserts the character #x1f514;
the only way to insert it via `C-x 8' is to hit TAB and then click on
the entry `BELL (BEL)' in the *Completions* buffer.  So the *Help* is at
best misleading.

Steve Berman