pokeSockAddr check ignores multi-char Unicode bytes and forgets about NULL terminator

[nh2]

network/Network/Socket/Types.hsc

Lines 1158 to 1161 in 2d5ebe6

	pokeSockAddr p sa@(SockAddrUnix path) = do
	when (length path > unixPathMax) $ error
	$ "pokeSockAddr: path is too long in SockAddrUnix " <> show path
	<> ", length " <> show (length path) <> ", unixPathMax " <> show unixPathMax

The check length path > unixPathMax seems wrong:

• It should be >= because there needs to be a Byte available for the trailing \0.
• The comparison is made on Unicode chars (String) instead of C chars (Bytes)

https://hackage.haskell.org/package/network-3.2.1.0/docs/Network-Socket.html#v:SockAddrUnix says

The path must have fewer than 104 characters. All of these characters must have code points less than 256.

but the check should enforce this properly.