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

Johannes Schindelin [off-list ref] writes:

So you meant to say that substitute_branch_name() calls 
interpret_branch_name(), so the change should be in the latter.  (This is 
supposed to be the summary of your 4 paragraphs.)

Not quite.  What I was asking was:

	*PROVIDED* *IF* you wanted to keep the same semantics between
         them, then you would have patched i-b-n, but you didn't.  Was there
         a reason callers of s-b-n should know about @{u} but callers of i-b-n
	shouldn't?

Expected answer was either:

	(a) Codepath X that uses i-b-n shouldn't interpret @{upstream} as
            a symbolic name given by the user, but it should treat it as a
            mere SHA-1 expression instead for *this and that* reason.
            Otherwise we will see *this* breakage when the user does
            *that*.  That is why i-b-n doesn't know about the new syntax;
            or

	(b) It was a thinko; all codepaths that use i-b-n should know the
            new syntax as they _are_ interested in learning the symbolic
            name when the user gives @{upstream}.