Lists with a single empty item (i.e. +, -, *, 1234.) shouldn't be considered Markdown #1265
Description
Description
When Markdown is turned on, sending a message containing only digits followed
by a period produces a formatted_body containing HTML for an ordered list
with a single empty item.
This seems wrong because a user typing something like 2018.<enter> will
almost never mean "an ordered list with an empty item". Furthermore, it is
related to at least two usability bugs that can look very bad to the end user:
-
Wrong rendering of ordinals with >= 3 digits in Riot Web
This is a separate bug that could (and should) be fixed, but it is also
particularly bad in combination with this bug, because typing something
common like2018.can trigger it. -
Riot Android renders such messages as empty, as described in Messages containing only digits followed by a period are invisible riot-android#2285.
They, however, are unsure what to do with it. In a previous Riot Android
version, it at least rendered the list ordinal correctly even when the list
item is empty (like Riot Web), but now it has stopped working again.I consider this a separate bug too, since empty list items should
nevertheless get their ordinal rendered.
I propose that messages of form ^[0-9]+\.\s*$ are considered a special case
and not treated as Markdown. This seems to me to follow the principle of least
surprise to the average user. In any case, the Riot clients should all behave
the same.
An example event:
{
"origin_server_ts": 1540893691521,
"sender": "@dkasak:termina.org.uk",
"event_id": "$15408936912708mMjYL:termina.org.uk",
"unsigned": {
"age": 113,
"transaction_id": "m1540893692103.11"
},
"content": {
"body": "2018.",
"msgtype": "m.text",
"formatted_body": "<ol start=\"2018\">\n<li></li>\n</ol>\n",
"format": "org.matrix.custom.html"
},
"type": "m.room.message",
"room_id": "!DCRUrRQxGhHTRwlYla:termina.org.uk"
}
Steps to reproduce
- Ensure Markdown is turned on.
- Type
2018.and press Enter. - Notice that it has a
formatted_bodyas described above. - Notice that it renders as an empty message in Riot Android.
I expect this to produce an m.text event without a formatted_body. Instead,
it should only have a body with the contents "2018.".
Version information
- Platform: both web and desktop
For the web app:
- Browser: Firefox 63
- OS: Arch Linux
- URL: riot.im/app
For the desktop app:
- OS: Arch Linux
- Version: 0.17.2