I've always written OVS code this way, so this just codifies it so that
others know.
...
}
+Functions that destroy an instance of a dynamically-allocated type
+should accept and ignore a null pointer argument. Code that calls
+such a function (including the C standard library function free())
+should omit a null-pointer check. We find that this usually makes
+code easier to read.
+
FUNCTION PROTOTYPES