Merge #4

4: fix support for text-2.0 r=nyghtly-derek a=jali-clarke

inspired by winterland1989#54 @ upstream (of which this is a fork), should fix segfaults for any builds using this library

Co-authored-by: Jinnah Ali-Clarke <[email protected]>

Database/MySQL/Protocol/Escape.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE CPP #-}
 
 {-|
 Module      : Database.MySQL.Protocol.Escape
@@ -32,6 +33,7 @@ The @\%@ and @\_@ sequences are used to search for literal instances of @%@ and
 
 module Database.MySQL.Protocol.Escape where
 
+import           Control.Monad            (forM_)
 import           Data.ByteString          (ByteString)
 import qualified Data.ByteString.Internal as B
 import           Data.Text                (Text)
@@ -44,6 +46,42 @@ import           Foreign.Storable         (peek, poke, pokeByteOff)
 import           GHC.IO                   (unsafeDupablePerformIO)
 
 escapeText :: Text -> Text
+#if MIN_VERSION_text(2,0,0)
+escapeText (T.Text arr off len)
+    | len <= 0  = T.empty
+    | otherwise =
+        let (arr', len') =  TA.run2 $ do
+                marr <- TA.new (len * 2)
+                loop arr (off + len) marr off 0
+        in T.Text arr' 0 len'
+  where
+    escape c marr ix = do
+        TA.unsafeWrite marr ix 92
+        TA.unsafeWrite marr (ix+1) c
+
+    loop oarr oend marr !ix !ix'
+        | ix == oend = return (marr, ix')
+        | otherwise  = do
+            let c = TA.unsafeIndex oarr ix
+                cs = c : [ TA.unsafeIndex oarr (ix+1) | c >= 0xC0 ]
+                      ++ [ TA.unsafeIndex oarr (ix+2) | c >= 0xE0 ]
+                      ++ [ TA.unsafeIndex oarr (ix+3) | c >= 0xF0 ]
+                go2 = loop oarr oend marr (ix+1) (ix'+2)
+                goN = do
+                  forM_ (zip [0..4] cs) $ \(di,c') -> TA.unsafeWrite marr (ix' + di) c'
+                  loop oarr oend marr (ix + length cs) (ix' + length cs)
+            if  | c == 0
+                    || c == 39
+                    || c == 34 -> escape c   marr ix' >> go2 -- \0 \' \"
+                | c == 8       -> escape 98  marr ix' >> go2 -- \b
+                | c == 10      -> escape 110 marr ix' >> go2 -- \n
+                | c == 13      -> escape 114 marr ix' >> go2 -- \r
+                | c == 9       -> escape 116 marr ix' >> go2 -- \t
+                | c == 26      -> escape 90  marr ix' >> go2 -- \Z
+                | c == 92      -> escape 92  marr ix' >> go2 -- \\
+
+                | otherwise    -> goN
+#else
 escapeText (T.Text arr off len)
     | len <= 0  = T.empty
     | otherwise =
@@ -77,6 +115,7 @@ escapeText (T.Text arr off len)
                 | c == 92      -> escape 92  marr ix' >> go2 -- \\
 
                 | otherwise    -> TA.unsafeWrite marr ix' c >> go1
+#endif
 
 escapeBytes :: ByteString -> ByteString
 escapeBytes (B.PS fp s len) = unsafeDupablePerformIO $ withForeignPtr fp $ \ a ->