git rebase command and docs questions

Hi,

I have few questions about rebase and its help content:

1. In case of this situation

o---o---o---o---o  master
        \
         o---o---o---o---o  next
                          \
                           o---o---o  topic

“git rebase master topic” says: The current branch topic is up-to-date.

This message seems to be confusing and even incorrect. The actual problem, as I understand, is that topic branch is not a direct descendant of the master branch, therefore “git rebase –onto master next topic” should be used instead. Is there a way for git to identify this problem more correctly and print more helpful error message?

2. The rebase help is a bit confusing in its “–onto” option part.
Initially help says that the form:

git rebase master topic

is a shorthand for git checkout topic, git rebase master

But, in “git rebase –onto master next topic” the meaning of the “next topic” parameters is different: as I understand, it actually specifies a range of commits from next to topic,  because –onto changes the way the whole command is working, but it is not clarified in help. Is that correct understanding?

3. The part of help from “Another example of --onto option is to
rebase part of a branch.” Is actually demonstrating absolutely the
same thing as the one before with the only difference that in the
second example the master has not advanced. There was probably some
different intention, but currently it looks like confusing
duplication.

Thanks, Eugene