Add a notification rate limiter.

[tseli0s]

Prerequisites

• I have searched open and closed issues for duplicates.

Feature

Is your feature request related to a problem? Please describe.
Technically, yes. The problem is that a malicious application can crash the entire system by spamming notifications. Just had this with a Wine program happen.

Describe the solution you'd like
A rate limiter can do the job. The server will refuse to handle any new notifications from a process for some time, if that process already sent over for example 20 notifications within a minute. Every minute that counter resets and the process can start sending notifications again.

The only problem is how would a developer would handle such an error. Afaik libnotify at least would have to be modified, I don't know if DBus would too.

Existing work
Maybe, but I don't know.

Describe alternatives you've considered
None apart from just letting someone's OS to crash.

Additional context
-

[janxkoci]

Interesting - I recall @jeremypw once generated 2000 notifications to test a bug and he didn't mention any crash.

Also, you said crash - do you have a backtrace?