Telegram silently routes a copyMessage aimed at a deleted forum topic
into the chat's General topic with NO error, so the bot's error-based
recreate never fired — the user's next message landed in General with no
card. Confirmed against the prod bot logs: a relay after a topic deletion
logged neither "relay to topic failed" nor "topic gone, reopening".
Probe topic liveness before reusing it: re-applying the info card's reply
markup is a no-op that errors only when the card (hence the topic) is
gone, so the bot detects the deletion and reopens the topic + card rather
than relying on the (absent) copy error. The post-copy recreate stays as
a race backstop.
The topic info card built the profile link as `tg://user?id=`, which
clients render as dead text for a user they don't already know (the
test-vs-prod difference an operator saw), and it put the raw display
name through HTML — so a name starting with "/" was auto-detected as a
tappable bot command that fired when tapped.
Render the card with message entities instead: the display name is
covered by a `text_mention` entity (the reliable way to mention a
username-less user the bot has already seen — it messaged the bot),
which links the profile AND, because the name sits inside an entity,
suppresses the "/command" and "@mention" auto-detection on it. Drop the
HTML parse mode and the tg:// link. Entity offsets are UTF-16.
developer
Ilia Denisov