[வியாழன் மார்ச் 31, 2022] Eli Zaretskii wrote:

>> From: Visuwesh <visuweshm@gmail.com>
>> Date: Thu, 31 Mar 2022 09:07:30 +0530
>> 
>> I cannot seem to reproduce this from emacs -Q, nor do I see this issue
>> when I start Emacs up (I use the daemon if that makes a difference [2]).
>> [...]
>> It naturally shows up after using Emacs for a while, sometimes reopening
>> the frame fixes the clipping problems, sometimes I have to reevaluate
>> the set-fontset-font form to fix it.  And this issue isn't font-specific
>> as well: I had the same problem with "Noto Serif."  I would highly any
>> hints towards nailing the problem down; I'm really out of ideas.
>
> When it happens, does it help to do the below?
>
>   M-: (clear-composition-cache) RET
>

It does not really help.  I saw a slight change in the "gaps" between
characters.  But I do believe the issue might be do with some kind of
caching: when I read Tamil text, I tend to increase the buffer text size
using C-x C-+.  Currently, Emacs does not display the text properly but
if I zoom in enough (so that the scale is similar/same as the one that
was used in another buffer), the text is shaped properly.  Please see
the following screenshots,

before text-scale-mode: