From f8fdd180c8ce9f95507dc16873186743e5bc6d03 Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <adrian@openwork.nz>
Date: Sat, 30 Sep 2023 15:36:08 +1300
Subject: [PATCH] Attempted segfault fix.

---
 Graphics/Text/Font/Choose/CharSet.hs | 11 ++++++-----
 Graphics/Text/Font/Choose/FontSet.hs |  2 --
 cbits/pattern.c                      |  9 ++++++++-
 fontconfig-pure.cabal                |  2 +-
 4 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/Graphics/Text/Font/Choose/CharSet.hs b/Graphics/Text/Font/Choose/CharSet.hs
index 91d4326..ae86ffc 100644
--- a/Graphics/Text/Font/Choose/CharSet.hs
+++ b/Graphics/Text/Font/Choose/CharSet.hs
@@ -8,7 +8,8 @@ import Data.Word (Word32)
 import Foreign.Ptr
 import Control.Exception (bracket)
 import Control.Monad (forM)
-import Foreign.Marshal.Alloc (alloca, allocaBytes)
+import Foreign.Marshal.Alloc (alloca)
+import Foreign.Marshal.Array (allocaArray)
 import GHC.Base (unsafeChr)
 import Data.Char (ord, isHexDigit)
 import Numeric (readHex)
@@ -61,10 +62,10 @@ foreign import ccall "FcCharSetAddChar" fcCharSetAddChar :: CharSet_ -> Word32 -
 thawCharSet :: CharSet_ -> IO CharSet
 thawCharSet chars'
     | chars' == nullPtr = return Set.empty
-    | otherwise = allocaBytes fcCHARSET_MAP_SIZE $ \iter' -> alloca $ \next' -> do
+    | otherwise = allocaArray fcCHARSET_MAP_SIZE $ \iter' -> alloca $ \next' -> do
         first <- fcCharSetFirstPage chars' iter' next'
         let go = do
-                ch <- fcCharSetNextPage chars' iter' next';
+                ch <- fcCharSetNextPage chars' iter' next'
                 if ch == maxBound then return []
                 else do
                     chs <- go
@@ -72,9 +73,9 @@ thawCharSet chars'
         if first == maxBound then return Set.empty else do
             rest <- go
             return $ Set.fromList $ map (unsafeChr . fromIntegral) (first:rest)
-foreign import ccall "FcCharSetFirstPage" fcCharSetFirstPage ::
+foreign import ccall "my_FcCharSetFirstPage" fcCharSetFirstPage ::
     CharSet_ -> Ptr Word32 -> Ptr Word32 -> IO Word32
-foreign import ccall "FcCharSetNextPage" fcCharSetNextPage ::
+foreign import ccall "my_FcCharSetNextPage" fcCharSetNextPage ::
     CharSet_ -> Ptr Word32 -> Ptr Word32 -> IO Word32
 foreign import ccall "my_FcCHARSET_MAP_SIZE" fcCHARSET_MAP_SIZE :: Int
 
diff --git a/Graphics/Text/Font/Choose/FontSet.hs b/Graphics/Text/Font/Choose/FontSet.hs
index 044a727..7c19b0e 100644
--- a/Graphics/Text/Font/Choose/FontSet.hs
+++ b/Graphics/Text/Font/Choose/FontSet.hs
@@ -55,8 +55,6 @@ withFontSets' (fonts:fontss) i fontss' cb = withFontSet fonts $ \fonts' -> do
 
 thawFontSet :: FontSet_ -> IO FontSet
 thawFontSet fonts' = do
-    -- Very hacky, but these debug statements must be in here to avoid segfaults.
-    -- FIXME: Is there an alternative?
     n <- get_fontSet_nfont fonts'
     if n == 0 then return []
     else
diff --git a/cbits/pattern.c b/cbits/pattern.c
index 6754bda..28184bf 100644
--- a/cbits/pattern.c
+++ b/cbits/pattern.c
@@ -2,7 +2,14 @@
 #include <stddef.h>
 
 int my_FcCHARSET_MAP_SIZE() {
-    return FC_CHARSET_MAP_SIZE*sizeof(FcChar32);
+    return FC_CHARSET_MAP_SIZE;
+}
+
+FcChar32 my_FcCharSetFirstPage(const FcCharSet *a, FcChar32 *map, FcChar32 *next) {
+    return FcCharSetFirstPage(a, map, next);
+}
+FcChar32 my_FcCharSetNextPage(const FcCharSet *a, FcChar32 *map, FcChar32 *next) {
+    return FcCharSetNextPage(a, map, next);
 }
 
 FcBool my_FcPatternAdd(FcPattern *p, const char *object,
diff --git a/fontconfig-pure.cabal b/fontconfig-pure.cabal
index 3e49167..277e35f 100644
--- a/fontconfig-pure.cabal
+++ b/fontconfig-pure.cabal
@@ -10,7 +10,7 @@ name:                fontconfig-pure
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.1.1.1
+version:             0.2.0.0
 
 -- A short (one-line) description of the package.
 synopsis:            Pure-functional language bindings to FontConfig
-- 
2.30.2