What is the question?
We do regularly copy whole space when we do new version and just modify what is relevant.
for example AS70 was copied to AS71 and modified, then we copied that to AS72 and add some more stuff.
WFLY8 was copied from AS72 and modified to reflect changes in WildFly 8
So does this help you?
Question is: there is a published book which has some content copied from JBoss AS documentation even without giving the source. Is this allowed? Is it possible to use any documentation part in such scenario, for example mentioning the source?
Any chance the autor of the book is the same author who contributed to the AS documentation? E.g. for this book it wouldn't have been a problem, it's authors work and he can both contribute it and make it part of his book.