Push merges?

Hello all,

I've been getting to know git and I've stumbled across a "problem" and I haven't yet been able to find a solution. For example, say I have a branch "base" and two branches of that "foo" and "bar". I make some change in "base", commit it, and now I would like to have it in both "foo" and "bar". Is there a command that rather than get another branch and merge with the current branch will instead take the current branch and apply a merge on other branches? I've done google searches and looking through documentation and tutorials and I can't seem to find an answer one way or another. I wanted to make sure that before I go write some script to handle it that what I am looking for isn't already a feature.

Thank you, Ryan