From 43343c151f9824a44bd6e353610fdeb23f910c72 Mon Sep 17 00:00:00 2001
From: Herbert Valerio Riedel <hvr@gnu.org>
Date: Thu, 7 Aug 2014 12:23:07 +0200
Subject: [PATCH] Use correct POSIX offset-type for tell/seekdir
This fixes the FFI imports to use the proper `CLong` type over the
previous incorrect `COff` type, as using the wrong argument type can
cause problems when the `long` and `off_t` types have different size.
Historic note from the manual page:
In glibc up to version 2.1.1, the return type of telldir() was off_t.
POSIX.1-2001 specifies long, and this is the type used since glibc
2.1.2 (released in 1999).
---
System/Posix/Directory/Common.hsc | 8 ++++----
changelog.md | 2 ++
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/System/Posix/Directory/Common.hsc b/System/Posix/Directory/Common.hsc
index 86d87ca..7cc61af 100644
--- a/System/Posix/Directory/Common.hsc
+++ b/System/Posix/Directory/Common.hsc
@@ -62,20 +62,20 @@ newtype DirStreamOffset = DirStreamOffset COff
#ifdef HAVE_SEEKDIR
seekDirStream :: DirStream -> DirStreamOffset -> IO ()
seekDirStream (DirStream dirp) (DirStreamOffset off) =
- c_seekdir dirp off
+ c_seekdir dirp (fromIntegral off) -- TODO: check for CLong/COff overflow
foreign import ccall unsafe "seekdir"
- c_seekdir :: Ptr CDir -> COff -> IO ()
+ c_seekdir :: Ptr CDir -> CLong -> IO ()
#endif
#ifdef HAVE_TELLDIR
tellDirStream :: DirStream -> IO DirStreamOffset
tellDirStream (DirStream dirp) = do
off <- c_telldir dirp
- return (DirStreamOffset off)
+ return (DirStreamOffset (fromIntegral off)) -- TODO: check for overflow
foreign import ccall unsafe "telldir"
- c_telldir :: Ptr CDir -> IO COff
+ c_telldir :: Ptr CDir -> IO CLong
#endif
changeWorkingDirectoryFd :: Fd -> IO ()
diff --git a/changelog.md b/changelog.md
index ae5b726..c481922 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,4 @@
+<<<<<<< HEAD
# Changelog for [`unix` package](http://hackage.haskell.org/package/unix)
## 2.7.0.2 *TBA*
@@ -9,6 +10,7 @@
CPP macros for required getgrgid_r and getgrnam_r functions definition
so the fix is to change from C ABI calling convention to C API calling
convention
+ * Fix potential type-mismatch in `telldir`/`seekdir` FFI imports
## 2.7.0.1 *Mar 2014*
--
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