How to catch-up named mercurial branch from default branch without merging the two into one?

I have two branches in mercurial..

default    named
|r1
|r2
|r3 --------         named branch created here.
|            |r4
|            |r5
| r6         |
|            |r7
|            |
-----------> | r8    How do I achieve this catch-up?
|            |

I want to update the named branch from default, but I'm not ready to merge the branches yet. How do I achieve this?

Edit:

Addition开发者_如何学编程ally, what would the operation be using the GUI? Is it.. right-click r6, merge with..., r8,... then what? commit to named branch?

hg merge default from your named branch.