Signal uses half-width katakana characters instead of full-width katakana characters

[lokesh-krishna]

Using a supported version?

• [X] I have searched searched open and closed issues for duplicates.
• [X] I am using Signal-Desktop as provided by the Signal team, not a 3rd-party package.

Overall summary

When writing in Japanese, Signal uses half-width characters for katakana instead of full-width ones that other applications do. This is despite using an IME to enter full-width characters.

Steps to reproduce

1. Go to any chat
2. Enter any katakana characters

Expected result

Characters are rendered as full-width katakana

Actual result

Characters are instead rendered as half-width katakana, which affects readability.

Screenshots

Half-width katakana in Signal

WhatsApp uses full-wdith katakana.

Signal version

7.16.0beta.2-1

Operating system

Linux

Version of Signal on your phone

7.11.1

Link to debug log

Not applicable

[beantaco]

I have no good idea of what could cause this.

In case it's an IME issue, just a few questions related to IME that might help with understanding the issue:

• Which IME(s) are you using?
  • input buses
  • Japanese input methods
• Is there a chance that you have more than one IME and that it (beginning at some point in time) automatically switches depending on what application is in focus?
• Does your IME switch between input modes (hiragana, half-with katakana, full-with katakana, direct input and so on) depending on what application is in focus?
• When typing in katakana, do you use katakana mode to type in katakana directly, or do you type hiragana and then convert (with space bar or some other key)?
• Assuming you use conversion, what happens after you do a convert to full-width katakana, and then want to type in katakana again?

Otherwise, did this change happen immediately after updating your Signal Desktop? Does using the stable (non-beta) version make the issue go away?

[lokesh-krishna]

• I'm using Fcitx5 with Mozc as the Japanese input method
• Um, I only have Fcitx5 installed on my system.
• The IME defaults to hiragana. I have to manually switch entered text to katakana using F7.
• I type in Hiragana and then use F7 to convert to katakana. Fcitx5 also has the option to convert to half-width katakana (F8).

I tried F8 for the first time today and it resulted in katakana that were even narrower. Attaching a screenshot to explain what I mean.

Message 1 is Hiragana. Message 2 is Katakana (converted from Hiragana using F7) Message 3 is Half-Width Katakana (converted from Hiragana using F8)

Message 2 is narrower than katakana displayed anywhere else on my system. That's what made me assume that Signal was using half-width katakana but actually entering half-width katakana results in katakana that are even narrower, which means what I assumed were half-width was actually full-width. Just narrower than what I was expecting.

That makes me wonder if the problem here is that Signal isn't picking the right font for full width katakana? Even katakana messages that I receive from others are displayed narrower than they are anywhere else in the system.

[beantaco]

Looks to be a font issue, not an IME related issue. The full-width katakana font looks bolder, not just narrower.

The half-width katakana text appears the same as in my Signal client, so I believe it is being rendered correctly.

When did you first witness the katakana rendering issue? After installing 7.16.0beta.2-1 or over a prolonged period? I'm using non-beta 7.16.0, so maybe you can try that to see if the issue persists.

Identifying the offending font might help too. Does anyone know what it is?

[trevor-signal]

@beantaco can you share debug logs?

[beantaco]

I think it's not an issue with my client.

The picture below is my rendering (increased to 125%) of

あいうえお しぐなる
アイウエオ シグナル
ｱｲｳｴｵ ｼｸﾞﾅﾙ

I'm reluctant to share my debug log. Is there a specific portion of the log you have in mind?