I have no idea why this needs collectgarbage() to be called twice.
On the other hand, I can explain the change in tooltip.lua. Lua 5.2 introduced
"ephermeron tables". This means that in the following sitation, lua 5.2 can
collect the entry from the table, while 5.1 keeps the entry alive, because the
table has a strong reference to the value and that in turn has a strong
reference to the key:
t = setmetatable({}, { __mode = "k"})
do
local k = {}
t[k] = function() print(k) end
end
collectgarbage("collect")
print(next(t, nil))
To handle this incompatibility, this commit just removes the whole indirection
through the module-level variable "data".
Signed-off-by: Uli Schlachter <psychon@znc.in>