LibSub never notifies empty strings
Description
The data changed callback is never called when the new value to notify is an empty string.
Analysis
The function Helpers_NewValueFromDataValue
returns SOPC_STATUS_OUT_OF_MEMORY
when SOPC_String_GetCString
returns NULL
.
However, the latter function returns NULL
on empty string, which is a legit behavior.
Fixes
Do not allocate a buffer when the string/bytestring is NULL
(or its Length <= 0
), leave value
to NULL
, set status to OK
.