Merge branch 'ct/prompt-untracked-fix'

The prompt script (in contrib/) did not show the untracked sign
when working in a subdirectory without any untracked files.

* ct/prompt-untracked-fix:
  git prompt: use toplevel to find untracked files

contrib/completion/git-prompt.sh

@@ -487,7 +487,7 @@ __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 --error-unmatch -- ':/*' >/dev/null 2>/dev/null
 		then
 			u="%${ZSH_VERSION+%}"
 		fi