mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.

---
summary: Prevent unaffiliated MUC participants from sending PMs
---

# Introduction

This module prevents unaffiliated users from sending private messages in
chat rooms, unless someone with an affiliation (member, admin etc)
messages them first.

# Configuration

The module doesn't have any options, just load it onto a MUC component.

``` lua
Component "muc"
modules_enabled = {
    "muc_block_pm";
}
```

# Compatibility

    Branch State
  -------- -----------------
       0.9 Works
      0.10 Should work
      0.11 Should work