Icons in subject message rendered too big

[Carroarmato0]

When an icon is deplayed inside the Subject field of a message Thunderbird renders it too big.

Example of a UTF8 character being rendered as way too big icon in the message source:

subject: =?utf-8?q?=F0=9F=94=8C?= Het is weer gelukt: veiling was een succes!

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: thunderbird 1:52.7.0+build1-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: carroarmato0 1641 F.... pulseaudio
 /dev/snd/controlC0: carroarmato0 1641 F.... pulseaudio
BuildID: 20180416164209
Channel: Unavailable
CurrentDesktop: ubuntu:GNOME
Date: Fri Apr 27 17:17:59 2018
ExecutablePath: /usr/lib/thunderbird/thunderbird
Extensions: extensions.sqlite corrupt or missing
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
InstallationDate: Installed on 2018-04-27 (0 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
IpRoute:
 default via 192.168.20.1 dev wlp3s0 proto dhcp metric 600
 169.254.0.0/16 dev wlp3s0 scope link metric 1000
 192.168.20.0/24 dev wlp3s0 proto kernel scope link src 192.168.20.220 metric 600
Locales: extensions.sqlite corrupt or missing
PrefSources: prefs.js
Prefs:
 extensions.lastAppVersion: "52.7.0" (prefs.js)
 network.cookie.prefsMigrated: true (prefs.js)
 network.predictor.cleaned-up: true (prefs.js)
 places.database.lastMaintenance: 1524839666 (prefs.js)
 places.history.expiration.transient_current_max_pages: 122334 (prefs.js)
Profiles: Profile0 (Default) - LastVersion=52.7.0/20180416164209 (In use)
RunningIncompatibleAddons: False
SourcePackage: thunderbird
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/25/2016
dmi.bios.vendor: LENOVO
dmi.bios.version: JBET60WW (1.24 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20BX004QMB
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40705 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrJBET60WW(1.24):bd05/25/2016:svnLENOVO:pn20BX004QMB:pvrThinkPadT450s:rvnLENOVO:rn20BX004QMB:rvrSDK0J40705WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T450s
dmi.product.name: 20BX004QMB
dmi.product.version: ThinkPad T450s
dmi.sys.vendor: LENOVO

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Orkhan Guliyev (orkhan-c)]

Yes, I have this problem too.