From db718eedcd144a799fa519d45055456852d1b97b Mon Sep 17 00:00:00 2001
From: Jonathan Lamothe <jonathan@jlamothe.net>
Date: Sun, 24 Oct 2021 14:28:41 -0400
Subject: [PATCH] properly encode non-ASCII characters with encodeString

---
 src/Network/GemServ.hs      | 25 ++++++++++++++-----------
 test/Network/GemServSpec.hs |  1 +
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/Network/GemServ.hs b/src/Network/GemServ.hs
index 9dcf8d5..0980419 100644
--- a/src/Network/GemServ.hs
+++ b/src/Network/GemServ.hs
@@ -33,9 +33,9 @@ module Network.GemServ (
 ) where
 
 import qualified Data.ByteString as BS
-import Data.ByteString.Builder (charUtf8, toLazyByteString)
+import Data.ByteString.Builder (charUtf8, stringUtf8, toLazyByteString)
 import qualified Data.ByteString.Lazy as BSL
-import Data.Char (ord, toLower)
+import Data.Char (chr, ord, toLower)
 import Data.List (find, intercalate)
 import Data.Maybe (fromJust)
 import qualified Data.Text as T
@@ -58,17 +58,20 @@ encodeRequest req =
 
 -- | add required escape sequences to a string
 escapeString :: String -> String
-escapeString = concatMap $ \ch ->
-  if ch `elem` unescaped
-  then [ch]
-  else '%' : toHex ch
+escapeString = concatMap
+  ( \n -> let ch = chr $ fromIntegral n in
+    if ch `elem` unescaped
+    then [ch]
+    else '%' : toHex n
+  ) . BSL.unpack . toLazyByteString . stringUtf8
   where
     unescaped = ['0'..'9'] ++ ['A'..'Z'] ++ ['a'..'z'] ++ "~-_."
-    toHex ch  = let
-      n    = ord ch
-      high = n `div` 16
-      low  = n `mod` 16
-      in [hexDigits !! high, hexDigits !! low]
+    toHex =
+      ( \n -> let
+        high = n `div` 16
+        low  = n `mod` 16
+        in [hexDigits !! high, hexDigits !! low]
+      ) . fromIntegral
 
 -- | decode an escaped string back to its original value
 unescapeString :: String -> Maybe String
diff --git a/test/Network/GemServSpec.hs b/test/Network/GemServSpec.hs
index b58c21f..0c6807a 100644
--- a/test/Network/GemServSpec.hs
+++ b/test/Network/GemServSpec.hs
@@ -75,6 +75,7 @@ escapeStringSpec = describe "escapeString" $ mapM_
   --  input,               expected
   [ ( "~foo-bar_baz.quux", "~foo-bar_baz.quux"        )
   , ( "foo:/?=&#%",        "foo%3a%2f%3f%3d%26%23%25" )
+  , ( "foo\xe9",           "foo%c3%a9"                )
   ]
 
 unescapeStringSpec :: Spec