0001-Fixed-a-stack-overflow-in-randomRs.patch

From 44ddcb44e675fa0979c94efe5364b4c5fc83fab0 Mon Sep 17 00:00:00 2001
From: Bas van Dijk <[email protected]>
Date: Fri, 19 Apr 2013 21:04:35 +0200
Subject: [PATCH 1/2] Fixed a stack-overflow in randomRs The following
 generated a stack-overflow exception:

  g <- getStdGen
  randomRs (0,10::Int) g !! 1000000

Because randomRs generated a list without forcing the generator. This
caused the generator to become a large chain of thunks which when
eventually forced caused the stack to overflow.

Thanks to Utkarsh Upadhyay and Thomas Schilling for assisting me in
finding and fixing this bug.
---
 System/Random.hs |    4 +++-
 random.cabal     |    4 +---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/System/Random.hs b/System/Random.hs
index 9a970c4..f2e8d25 100644
--- a/System/Random.hs
+++ b/System/Random.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE BangPatterns #-}
 #if __GLASGOW_HASKELL__ >= 701
 {-# LANGUAGE Trustworthy #-}
 #endif
@@ -280,7 +282,7 @@ class Random a where
   -- | Plural variant of 'randomR', producing an infinite list of
   -- random values instead of returning a new generator.
   randomRs :: RandomGen g => (a,a) -> g -> [a]
-  randomRs ival g = x : randomRs ival g' where (x,g') = randomR ival g
+  randomRs ival !g = case randomR ival g of (x, g') -> x : randomRs ival g'
 
   -- | Plural variant of 'random', producing an infinite list of
   -- random values instead of returning a new generator.
diff --git a/random.cabal b/random.cabal
index 9c7b63f..66b9688 100644
--- a/random.cabal
+++ b/random.cabal
@@ -22,11 +22,9 @@ Cabal-Version: >= 1.6
 Library
     exposed-modules:
         System.Random
-    extensions:	CPP
-    GHC-Options: -O2 
+    GHC-Options: -O2
     build-depends: base >= 3 && < 5, time
 
 source-repository head
     type:     git
     location: http://darcs.haskell.org/packages/random.git/
-
-- 
1.7.10.4

0002-UNPACK-the-Int32-fields-into-the-StdGen-constructor.patch

From 623cd94f69cbb1bcf0d578e6f8e3ee419b0f8e2b Mon Sep 17 00:00:00 2001
From: Bas van Dijk <[email protected]>
Date: Fri, 19 Apr 2013 21:15:22 +0200
Subject: [PATCH 2/2] UNPACK the Int32 fields into the StdGen constructor

---
 System/Random.hs |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/System/Random.hs b/System/Random.hs
index f2e8d25..a4d7f2c 100644
--- a/System/Random.hs
+++ b/System/Random.hs
@@ -190,8 +190,9 @@ instance of 'StdGen' has the following properties:
 
 -}
 
-data StdGen 
- = StdGen Int32 Int32
+data StdGen
+ = StdGen {-# UNPACK #-} !Int32
+          {-# UNPACK #-} !Int32
 
 instance RandomGen StdGen where
   next  = stdNext
-- 
1.7.10.4