quoted

I think other uses in Git declare a bunch of integer constants for the
bitfields, not an enum. Why? Because or-ing flags together creates a
value not in the enum…

We nowadays typically declare the flags as enum, but when accepting the
bitfield we use `unsigned`.

Good points! I have updated it to remove the name branch_mode_flags now,
define the enums and pass them around as unsigned now. Will be in the next
patch.

Harald