qga/vss-win32: Document the DLL requires non-null errp
requester.cpp uses this pattern to receive an error and pass it on to
the caller (err_is_set() macro peeled off for clarity):
... code that may set errset->errp ...
if (errset->errp && *errset->errp) {
... handle error ...
}
This breaks when errset->errp is null. As far as I can tell, it
currently isn't, so this is merely fragile, not actually broken.
The robust way to do this is to receive the error in a local variable,
then propagate it up, like this:
Error *err = NULL;
... code that may set err ...
if (err)
... handle error ...
error_propagate(errset->errp, err);
}
See also commit 5e54769, 0f230bf, a903f40.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
3 files changed
