Comment 0 for bug 2006756

Impact
------
Composite emoji (such as 🫱🏾 [Rightwards Hand: Medium-Dark Skin Tone]) are not rendered correctly. By "composite emoji", I mean emoji that are made up of multiple Unicode characters joined by "ZWJ". Composite emoji are used for skin tones, gender, flags, and a few other emoji.

The incorrect rendering can be seen in Ubuntu 22.04's default text editor, gedit, as extra vertical red and black lines after the character. Screenshot attached.

Test Case
---------
Install the update
Close Text Editor if it is open
Open Text Editor
Paste this character in Text Editor:
🫱🏾
It should display correctly without any extra vertical lines after it.

Other Info
----------
This was originally noticed while verifying https://launchpad.net/bugs/1990677

What Could Go Wrong
-------------------
This is a one line fix cherry-picked from pango 1.50.8

pango is a text rendering library in GTK. GTK is used for most of the apps in the default install for Ubuntu Desktop and several other Ubuntu desktop flavors. pango is also used by mutter which is a key component of GNOME Shell which provides the basic desktop environment for default Ubuntu. A critical enough bug in pango could make the desktop and apps unusuable because text wouldn't be readable. This is mitigated through build tests and autopkgtests.