bug#44466: 27.1; quail input fails at read-only boundary

[Eli Zaretskii]

> From: lg.zevlg@gmail.com
> Date: Sun, 8 Nov 2020 20:07:46 +0400
> Cc: dick.r.chiang@gmail.com, 44466@debbugs.gnu.org
> 
> > Any reason why pressing a key on a button should disregard the active
> > input method?  What if the button needs the user to type the character
> > which the input method would produce?  AFAIU, the patch we installed a
> > year ago makes this impossible.
> 
> The reason is the same as for read-only buffers, making single char bindings 
> work. For example if you change input method in image-mode and press “q” key 
> this will kill buffer, because correct command is executed.

If this is a feature, it should be documented somewhere.  Is it?