Punctuation marks are prefixed with backslashes in message body

[rom4nik]

Steps to reproduce

1. Go to a room
2. Type e.g. !ping or .,*"':;!? in message box
3. Send message

Outcome

What did you expect?

content.body in message has !ping value.

What happened instead?

{
    "content": {
        "body": "\\!ping",
        "format": "org.matrix.custom.html",
        "formatted_body": "!ping",
        "msgtype": "m.text"
    },
    [...]
}

Another example:

{
    "content": {
        "body": "\\.\\,\\*\\\"\\'\\:\\;\\!\\?",
        "format": "org.matrix.custom.html",
        "formatted_body": ".,*\"':;!?",
        "msgtype": "m.text"
    },
    [...]
}

btw, single backslashes are visible in reply previews. Can't bisect right now, but it might have been caused by #1172, since a build a few commits before that PR was merged didn't have this issue.

Your phone model

Google Pixel 3

Operating system version

Android 12

Application version and app store

5a0e0a8 (current develop branch)

Homeserver

Synapse 1.91.1

Will you send logs?

No

Are you willing to provide a PR?

No

[kittykat]

Same as element-hq/element-x-ios#1629

[frebib]

#1291 should fix this