From b398f05ecce64234c24abd9a6b64024d19d03392 Mon Sep 17 00:00:00 2001
From: fr33domlover <fr33domlover@riseup.net>
Date: Mon, 21 May 2018 20:54:05 +0000
Subject: [PATCH] Ignore line numbers when computing diff

---
 src/Vervis/Git.hs | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/Vervis/Git.hs b/src/Vervis/Git.hs
index 93521e9..e9f4dc5 100644
--- a/src/Vervis/Git.hs
+++ b/src/Vervis/Git.hs
@@ -217,28 +217,39 @@ ep2fp = T.unpack . decodeUtf8 . B.intercalate "/" . map toBytes
 unModePerm :: ModePerm -> Word32
 unModePerm (ModePerm w) = w
 
+data Line = Line
+    { lineNumber :: Int
+    , lineText   :: Text
+    }
+
+instance Eq Line where
+    Line _ t == Line _ s = t == s
+
+instance Ord Line where
+    Line _ t `compare` Line _ s = t `compare` s
+
 mkdiff :: [Text] -> [Text] -> [(Bool, Int, Hunk)]
 mkdiff old new =
     let eitherOldNew (Old a)    = Just $ Left a
         eitherOldNew (New a)    = Just $ Right a
         eitherOldNew (Both _ _) = Nothing
-        stripLineNumber = fmap snd
+        stripLineNumber = fmap lineText
         mkhunk' (adds, pairs, rems) = Hunk
             { hunkAddFirst   = stripLineNumber adds
             , hunkRemoveAdd  = map (stripLineNumber *** stripLineNumber) pairs
             , hunkRemoveLast = stripLineNumber rems
             }
-        line ((n, _):_, _                 , _)        = (True, n)
-        line ([]      , ((n, _) :| _, _):_, _)        = (False, n)
-        line ([]      , []                , (n, _):_) = (False, n)
-        line ([]      , []                , [])       = error "empty hunk"
+        line ((Line n _):_, _                     , _)            = (True, n)
+        line ([]          , ((Line n _) :| _, _):_, _)            = (False, n)
+        line ([]          , []                    , (Line n _):_) = (False, n)
+        line ([]          , []                    , [])           = error "empty hunk"
         mkhunk h =
             let (n, l) = line h
             in  (n, l, mkhunk' h)
     in  map (mkhunk . groupEithers . N.toList) $
         groupJusts $
         map eitherOldNew $
-        diff (zip [1..] old) (zip [1..] new)
+        diff (zipWith Line [1..] old) (zipWith Line [1..] new)
 
 accumEdits :: BlobStateDiff -> [Edit] -> [Edit]
 accumEdits (OnlyOld bs) es =