From 655074d1c0f8ac3b13021157a1def3b2d15f60f8 Mon Sep 17 00:00:00 2001
From: Lennart Spitzner <hexagoxel@hexagoxel.de>
Date: Thu, 10 Aug 2017 13:09:39 +0200
Subject: [PATCH] Fix comment insertion error introduced in 91b9a240

---
 src-literatetests/tests.blt                   | 11 ++++++
 .../Haskell/Brittany/Internal/Backend.hs      |  3 --
 .../Haskell/Brittany/Internal/BackendUtils.hs | 37 ++++++++-----------
 3 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/src-literatetests/tests.blt b/src-literatetests/tests.blt
index 8d9064e..1f2ab6e 100644
--- a/src-literatetests/tests.blt
+++ b/src-literatetests/tests.blt
@@ -1006,6 +1006,17 @@ layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauseDocs = do
        , let guardPart = singleLineGuardsDoc guards
        ]
 
+#test comment-testcase-17
+{-# LANGUAGE MultiWayIf #-}
+func = do
+  let foo = if
+        | Constuctoooooooooooooooooooooooooooooooooooor `elem` artics -- TODO
+                                                                      -> max
+          (defLen - 0.2) -- TODO
+          (defLen * 0.8)
+        | otherwise -> max (defLen - 0.05) (defLen * 0.95) -- TODO
+  return True
+
 
 ###############################################################################
 ###############################################################################
diff --git a/src/Language/Haskell/Brittany/Internal/Backend.hs b/src/Language/Haskell/Brittany/Internal/Backend.hs
index e9114cc..f0b6403 100644
--- a/src/Language/Haskell/Brittany/Internal/Backend.hs
+++ b/src/Language/Haskell/Brittany/Internal/Backend.hs
@@ -167,7 +167,6 @@ layoutBriDocM = \case
       Just []     -> when allowMTEL $ moveToExactAnn annKey
       Just priors -> do
         -- layoutResetSepSpace
-        when (not $ null priors) $ layoutSetCommentCol
         priors
           `forM_` \(ExactPrint.Types.Comment comment _ _, ExactPrint.Types.DP (y, x)) ->
                     do
@@ -209,7 +208,6 @@ layoutBriDocM = \case
     case mComments of
       Nothing -> pure ()
       Just comments -> do
-        layoutSetCommentCol
         comments `forM_` \(ExactPrint.Types.Comment comment _ _, ExactPrint.Types.DP (y, x)) ->
           do
             -- evil hack for CPP:
@@ -241,7 +239,6 @@ layoutBriDocM = \case
     case mComments of
       Nothing -> pure ()
       Just comments -> do
-        layoutSetCommentCol
         comments `forM_` \(ExactPrint.Types.Comment comment _ _, ExactPrint.Types.DP (y, x)) ->
           do
       -- evil hack for CPP:
diff --git a/src/Language/Haskell/Brittany/Internal/BackendUtils.hs b/src/Language/Haskell/Brittany/Internal/BackendUtils.hs
index c3712b1..a7d8594 100644
--- a/src/Language/Haskell/Brittany/Internal/BackendUtils.hs
+++ b/src/Language/Haskell/Brittany/Internal/BackendUtils.hs
@@ -184,27 +184,22 @@ layoutMoveToCommentPos
 layoutMoveToCommentPos y x = do
   traceLocal ("layoutMoveToCommentPos", y, x)
   state <- mGet
-  if Data.Maybe.isJust (_lstate_commentCol state)
-    then do
-      mSet state
-        { _lstate_curYOrAddNewline = case _lstate_curYOrAddNewline state of
-          Left i  -> if y == 0 then Left i else Right y
-          Right{} -> Right y
-        , _lstate_addSepSpace = Just $ case _lstate_curYOrAddNewline state of
-          Left{}  -> if y == 0 then x else _lstate_indLevelLinger state + x
-          Right{} -> _lstate_indLevelLinger state + x
-        }
-    else do
-      mSet state
-        { _lstate_curYOrAddNewline = case _lstate_curYOrAddNewline state of
-          Left i  -> if y == 0 then Left i else Right y
-          Right{} -> Right y
-        , _lstate_addSepSpace = Just
-          $ if y == 0 then x else _lstate_indLevelLinger state + x
-        , _lstate_commentCol = Just $ case _lstate_curYOrAddNewline state of
-          Left i  -> i + fromMaybe 0 (_lstate_addSepSpace state)
-          Right{} -> lstate_baseY state
-        }
+  mSet state
+    { _lstate_curYOrAddNewline = case _lstate_curYOrAddNewline state of
+      Left i  -> if y == 0 then Left i else Right y
+      Right{} -> Right y
+    , _lstate_addSepSpace      = if Data.Maybe.isJust (_lstate_commentCol state)
+      then Just $ case _lstate_curYOrAddNewline state of
+        Left{}  -> if y == 0 then x else _lstate_indLevelLinger state + x
+        Right{} -> _lstate_indLevelLinger state + x
+      else Just $ if y == 0 then x else _lstate_indLevelLinger state + x
+    , _lstate_commentCol       = Just $ case _lstate_commentCol state of
+      Just existing -> existing
+      Nothing       -> case _lstate_curYOrAddNewline state of
+        Left i  -> i + fromMaybe 0 (_lstate_addSepSpace state)
+        Right{} -> lstate_baseY state
+    }
+
 
 -- | does _not_ add spaces to again reach the current base column.
 layoutWriteNewline