Use more efficient way to find current branch name

This might have drawbacks in case we are in "detached head" state

zshrc.org

@@ -439,7 +439,10 @@ This needs to be diff'd among the versions
   }
 
   function git-current-branch () {
-    git status -b | head -n 1 | awk {'print $3'}
+      # do I want to give up on revision numbers in detached-head state?
+      git rev-parse --abbrev-ref HEAD | grep -v HEAD || \
+      git describe --exact-match HEAD 2> /dev/null || \
+      git rev-parse HEAD
   }
 #+end_src