bool luaQ_disconnect(lua_State*L, QObject*o, const char *s, int fi)

Disconnects the signal with signature s of Qt object o from the function located at index fi in the stack. When argument fi is zero, this function removes all connections from the specified signal to a Lua function. When argument s is null, this function removes all connections from the specified object to the specified function.

See also qt.disconnect(...).