z -b should not match current directory, close #56

Author: skywind3000

README.md

@@ -458,6 +458,7 @@ As you see, z.lua is the fastest one and requires less resource.
 
 ## History
 
+- 1.5.9 (2019-02-25): `z -b` should not match current directory (close #56).
 - 1.5.8 (2019-02-21): new `$_ZL_FZF_HEIGHT` to control `--height` parameter in fzf.
 - 1.5.7 (2019-02-21): rename `$_ZL_FZF_SORT` to `$_ZL_INT_SORT` it will affect both `-i` and `-I`.
 - 1.5.6 (2019-02-20): set `$_ZL_FZF_SORT` to 1 to sort directories by alphabet in fzf.

z.lua

@@ -4,7 +4,7 @@
 -- z.lua - a cd command that learns, by skywind 2018, 2019
 -- Licensed under MIT license.
 --
--- Version 1.5.8, Last Modified: 2019/02/21 12:08
+-- Version 1.5.9, Last Modified: 2019/02/25 23:17
 --
 -- * 10x faster than fasd and autojump, 3x faster than z.sh
 -- * available for posix shells: bash, zsh, sh, ash, dash, busybox
@@ -1555,6 +1555,7 @@ function cd_backward(args, options, pwd)
 			end
 			return os.path.normpath(path)
 		else
+			pwd = os.path.split(pwd)
 			local test = windows and pwd:gsub('\\', '/') or pwd
 			local key = windows and args[1]:lower() or args[1]
 			if not key:match('%u') then