== Steps to reproduce ==
In whatever application with comments, like a Maniphest Task:
1. Create a comment pasting `F270656`
2. Create another comment pasting `F270656`
== What happens ==
Visual message:
{F284706, size=full}
Text:
> Action With No Effect
> One of your actions has no effect:
>
> Transaction (of type "core:file") has no effect.
>
> Apply remaining actions?
== What should happen instead ==
No weird confirmation message.
== Why that happens ==
It seems this source code generates the "file reference":
https://we.phorge.it/source/phorge/browse/master/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php;ac99285c57a06ed5699b69242fd6588edd950112$2288-2291
Probably, if the file is already referenced, it tries to generate another file reference.
Possible solutions? (one of them)
1. Probably, something should ignore this redundant transaction
2. Probably, this transaction should not be generated