From cc4a215f837b39eeaf286a9fd603dd03d0e2c908 Mon Sep 17 00:00:00 2001
From: krangelov <kr.angelov@gmail.com>
Date: Thu, 5 Aug 2021 17:58:04 +0200
Subject: [PATCH] fix the memory leak in case of exceptions

---
 src/runtime/haskell/PGF2.hsc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/runtime/haskell/PGF2.hsc b/src/runtime/haskell/PGF2.hsc
index 5b7eaba22..d165b95e3 100644
--- a/src/runtime/haskell/PGF2.hsc
+++ b/src/runtime/haskell/PGF2.hsc
@@ -17,7 +17,7 @@ module PGF2 (-- * PGF
              PGF,readPGF
             ) where
 
-import Control.Exception(Exception,throwIO)
+import Control.Exception(Exception,throwIO,mask_)
 import PGF2.FFI
 
 import Foreign
@@ -30,7 +30,8 @@ import qualified Data.Map as Map
 readPGF :: FilePath -> IO PGF
 readPGF fpath =
   withCString fpath $ \c_fpath ->
-  allocaBytes (#size PgfExn) $ \c_exn -> do
+  allocaBytes (#size PgfExn) $ \c_exn ->
+  mask_ $ do
     c_pgf <- pgf_read c_fpath c_exn
     ex_type <- (#peek PgfExn, type) c_exn :: IO (#type PgfExnType)
     if ex_type == (#const PGF_EXN_NONE)
@@ -41,6 +42,7 @@ readPGF fpath =
                      ioError (errnoToIOError "readPGF" (Errno errno) Nothing (Just fpath))
              else do c_msg <- (#peek PgfExn, msg) c_exn
                      msg <- peekCString c_msg
+                     free c_msg
                      throwIO (PGFError msg)
 
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