[commit: base] master: Fix an off-by-one error in freeProgArgv (be1d813)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/be1d81350f96fab5de75114a049cf74dd4955fc7

>---------------------------------------------------------------

commit be1d81350f96fab5de75114a049cf74dd4955fc7
Author: Ian Lynagh <igloo at earth.li>
Date:   Wed May 2 13:39:26 2012 +0100

    Fix an off-by-one error in freeProgArgv

>---------------------------------------------------------------

 System/Environment.hs |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/System/Environment.hs b/System/Environment.hs
index 53f85f9..859f4a1 100644
--- a/System/Environment.hs
+++ b/System/Environment.hs
@@ -288,7 +288,8 @@ withProgArgv new_args act = do
 freeProgArgv :: Ptr CString -> IO ()
 freeProgArgv argv = do
   size <- lengthArray0 nullPtr argv
-  sequence_ [peek (argv `advancePtr` i) >>= free | i <- [size, size-1 .. 0]]
+  sequence_ [ peek (argv `advancePtr` i) >>= free
+            | i <- [size - 1, size - 2 .. 0]]
   free argv
 
 setProgArgv :: [String] -> IO (Ptr CString)