Instead of typing four capital letters "HEAD", you can say "@"
instead.
* fc/at-head:
sha1_name: compare variable with constant, not constant with variable
Add new @ shortcut for HEAD
sha1_name: refactor reinterpret()
sha1_name: check @{-N} errors sooner
sha1_name: reorganize get_sha1_basic()
sha1_name: don't waste cycles in the @-parsing loop
sha1_name: remove unnecessary braces
sha1_name: remove no-op
tests: at-combinations: @{N} versus HEAD@{N}
tests: at-combinations: increase coverage
tests: at-combinations: improve nonsense()
tests: at-combinations: check ref names directly
tests: at-combinations: simplify setup