From 012486c045784739cd71ae7a3b14bd29356bf6c3 Mon Sep 17 00:00:00 2001
From: Jonathan Lamothe <jlamothe1980@gmail.com>
Date: Tue, 1 Jan 2019 22:50:16 -0500
Subject: [PATCH] handle empty input string in mkPass

---
 src/Password.hs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/Password.hs b/src/Password.hs
index ce2d0e3..1e781da 100644
--- a/src/Password.hs
+++ b/src/Password.hs
@@ -323,12 +323,13 @@ isSpecial :: Char -> Bool
 isSpecial = not . isAlphaNum
 
 mkPass :: String -> PWPolicy -> String
-mkPass (x:xs) p = let p' = nextPolicy x p in
-  if p^.pwLength <= 0
+mkPass [] _ = "" -- this should never happen
+mkPass (x:xs) p = if p^.pwLength <= 0
   then ""
-  else if validatePWPolicy p'
-  then x : mkPass xs p'
-  else mkPass xs p
+  else let p' = nextPolicy x p in
+    if validatePWPolicy p'
+    then x : mkPass xs p'
+    else mkPass xs p
 
 mkPool :: B.ByteString -> String
 mkPool = toB64 . raw where