[Terenna]

I discovered the source of the taint I was experiencing with the community creation/destruction/joining. In the following function:

local function AddMessage(self, text, ...)
    --Remove player brackets
    text = text:gsub('|Hplayer:([^%|]+)|h%[([^%]]+)%]|h', '|Hplayer:%1|h%2|h')
    --Remove Away and Busy Tags
    text = text:gsub('<Away>', '')
    text = text:gsub('<Busy>', '')
 
    --Strip yells: says: from chat
    text = text:gsub('|Hplayer:([^%|]+)|h(.+)|h says:', '|Hplayer:%1|h%2|h:')
    text = text:gsub('|Hplayer:([^%|]+)|h(.+)|h yells:', '|Hplayer:%1|h%2|h:')
 
    --Shorten GMotD and change online/offline warnings
    text = text:gsub('Guild Message of the Day:', 'GMotD -')
    text = text:gsub('has come online.', '+')
    text = text:gsub('has gone offline.', '-')
 
    --channel replace (Trade and custom)
    text = text:gsub('|h%[(%d+)%. .-%]|h', '|h%1.|h')
 
    --url search
    text = text:gsub('([wWhH][wWtT][wWtT][%.pP]%S+[^%p%s])', '|cffffffff|Hurl:%1|h[%1]|h|r')
 
    return self.DefaultAddMessage(self, text, ...)
end

the last line

return self.DefaultAddMessage(self, text, ...)

is causing the taint. I don't doubt that the DefaultSetItemRef line you mentioned could also be causing taint, but none that I've come across yet. The above section I was able to reproduce 10/10 times and 0/10 times when I commented that one line of code out.

You wouldn't by chance know how I could better implement the AddMessage function to change things without causing taint, would you?