Merge branch 'sg/bash-prompt-untracked-optim'

Optimize computation of untracked status indicator by bash prompt
script (in contrib/).

* sg/bash-prompt-untracked-optim:
  bash prompt: faster untracked status indicator with untracked directories
  bash prompt: test untracked files status indicator with untracked dirs

contrib/completion/git-prompt.sh

@@ -491,7 +491,7 @@ __git_ps1 ()
 
 		if [ -n "${GIT_PS1_SHOWUNTRACKEDFILES-}" ] &&
 		   [ "$(git config --bool bash.showUntrackedFiles)" != "false" ] &&
-		   git ls-files --others --exclude-standard --error-unmatch -- ':/*' >/dev/null 2>/dev/null
+		   git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*' >/dev/null 2>/dev/null
 		then
 			u="%${ZSH_VERSION+%}"
 		fi