How to fix the really really round telegram bubbles and avatars and << >> -- stuff

fix_telegram.md

Credits goes to several people:

MrMetric - telegramdesktop/tdesktop#2235 (comment)

Afogal - https://gist.github.com/afogal/5ec200f46856b1b776a9a91601c00b87

SijmenSchoon - https://gist.github.com/SijmenSchoon/a24b453f001549bb14562de5078ae1bc

Streetwalrus - https://gist.github.com/Streetwalrus/bb2091bc5761a71e3b7c85d4e4a1ad99

Here is a bash/GDB script to patch Telegram Desktop 1.0 (tested on GNU/Linux only):

#/bin/bash

cp Telegram Telegram_backup

gdb --write ./Telegram << EOF

tbreak _ZN3App9initMediaEv
set {char}_ZN3App9msgRadiusEv=0xB8
set {int}(_ZN3App9msgRadiusEv+1)=3
set {char}(_ZN3App9msgRadiusEv+5)=0xC3

set {char}_Z25replaceStringWithEntitiesRK13QLatin1String5QCharR7QStringP5QListI12EntityInTextEb=0xC3

set {char}(_ZNK5Image10pixCircledEii+208)=1
EOF

If you want to run Telegram Desktop without modifying it, use this instead:

tbreak _ZN3App9initMediaEv
commands
	set {char}_ZN3App9msgRadiusEv=0xB8
	set {int}(_ZN3App9msgRadiusEv+1)=0
	set {char}(_ZN3App9msgRadiusEv+5)=0xC3

	set {char}_Z25replaceStringWithEntitiesRK13QLatin1String5QCharR7QStringP5QListI12EntityInTextEb=0xC3

	set {char}(_ZNK5Image10pixCircledEii+208)=1
end
run
detach
quit

Assuming you saved it to fix_telegram.gdb and Telegram Desktop is /usr/bin/telegram-desktop, run it like this:

gdb -x fix_telegram.gdb /usr/bin/telegram-desktop

This replaces the start of App::msgRadius with

mov $0x3, %eax
retq

In C++, that is return 3;

Explanation: 0xB8 means mov a number to %eax, 3 is the border radius, and 0xC3 is retq.

The start of void replaceStringWithEntities is replaced with retq, which disables these substitutions:

-- → — (em dash)
<< → «
>> → »

In Image::pixCircled, this line:

auto options = Images::Option::Smooth | Images::Option::Circled;

Is changed to:

auto options = Images::Option::Smooth;

Explanation: Smooth is 1, Circled is 4. That combination is 5. The byte is replaced with 1.