Subject: bug#56789: 28.1.90; Emoji composition problems with Harfbuzz 5.0.1-1

From: Robert Pluim <[email-masked]>
Date: Wed, 27 Jul 2022 10:08:54 +0200

>>>>> On Wed, 27 Jul 2022 06:10:06 +0000, Simon Pugnet <[email-masked]> said:

    Simon> I have just updated the Harfbuzz package in Arch Linux to
    Simon> harfbuzz-5.0.1-1 and I've noticed that some emojis are no longer
    Simon> displayed properly. From an initial investigation it appears to be
    Simon> only composed sequences that have problems.

    Simon> Instead of seeing a correctly composed emoji sequence as before, I now
    Simon> only see an empty box with a single-pixel border.

What does hb-view show? Something like

hb-view  --output-file=foo.svg --font-size=13 \
/usr/share/fonts/truetype/noto/NotoColorEmoji.ttf \
-u 1f469,200d,2764,fe0f,200d,1f468

and then display foo.svg

    Simon> I'm not sure if this is a bug in Emacs or Harfbuzz however it only
    Simon> started happening after the upgrade to 5.0.1-1

I donʼt think weʼve changed anything in this area recently. Certainly
not on the emacs-28 branch.

Robert
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