Re: default behaviour for `gitmerge` (no arguments)

Jeff King [off-list ref] writes:

Hmm. If we had the oft-discussed-but-never-agreed-upon shorthand for
"the upstream of" then we wouldn't need a special merge option. You
could just do:

  git merge %HEAD ;# (or git merge %, IIRC the proposal correctly)

I don't think "whatever _HEAD_ tracks" makes sense at the semantic level
(i.e. you don't do "branch.HEAD.merge") but a syntax for "whatever the
named _branch_ tracks" with "if a branch is not named, the current branch
is implied" (i.e. the one in parentheses) would.

It is an entirely different matter what the special syntax to trigger that
"upstream-ness" should be.  I vaguely recall @{upstream} or @{u} were the
concensus?