a positive (not negated) expression in if-else is more readable
correct inaccurate comment
Although it is true that a remotely created node will not have a 'local'
version, a node that is in sync will have a 'common' version, but not a
'local' version. This `else` case applies when there is nothing to merge,
and the 'remote' version can be stored as the new 'common' version.