Git/Magit: To which branch was a commit was originally committed?

[Michael Heerdegen]

Hello,

sorry if I'm missing something obvious.

I'm using Magit.  I follow the development of the Emacs repository.  I
have checked out master.  Because the release branch is regularly merged
into master, Git and Magit only tell me that all commits in the
graphical log are now contained in master.  When I click on a commit, in
the overview buffer of the commit, there is, AFAIU, no visible
indication to which branch this commit originally had been committed.
The graphical log also doesn't provide that information.  With other
words: I have no idea which branch is which.

What is the smartest way to find out?  (Hopefully without moving head
and such things...)

TIA,

Michael.