Incorrect branch information after fetching (local branch != remote branch)

Hi,

I have a copy of linux.git (Linux kernel) repository, with following
branch mapping:

  * master -> torvalds/master (Linus' mainline tree)
  * linux-5.*.y -> stable/linux-5.*.y (Stable tree)
  * net-next -> net-next/master (net-next tree)

When I fetch the mainline tree (torvalds/master), I get the expected
branch fetching info:

From https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
   672c0c5173427e..9050ba3a61a4b5  master     -> torvalds/master

When I fetch net-next, I get possibly incorrect branch name instead:

From https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
   6e28f56c0d1d97..0530a683fc858a  master     -> net-next/master

I expected that net-next (local branch name) is displayed instead of
master in this case.

Thanks.

-- 
An old man doll... just what I always wanted! - Clara