grub2/0089-grub-core-fs-minix.c-grub_minix_read_file-Simplify-a.patch

From 55a1c78a484d48c96291f0f2891745d8b60c2201 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Mon, 7 Jan 2013 11:27:18 +0100
Subject: [PATCH 089/482] 	* grub-core/fs/minix.c (grub_minix_read_file):
 Simplify arithmetics.

---
 ChangeLog            | 4 ++++
 grub-core/fs/minix.c | 8 ++++----
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index af29161..cdb3f3d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-01-07  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* grub-core/fs/minix.c (grub_minix_read_file): Simplify arithmetics.
+
 2013-01-05  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* grub-core/fs/ext2.c (grub_ext2_read_block): Use shifts rather than
diff --git a/grub-core/fs/minix.c b/grub-core/fs/minix.c
index 1e1c13b..a622533 100644
--- a/grub-core/fs/minix.c
+++ b/grub-core/fs/minix.c
@@ -261,12 +261,12 @@ grub_minix_read_file (struct grub_minix_data *data,
   /* Adjust len so it we can't read past the end of the file.  */
   if (len + pos > GRUB_MINIX_INODE_SIZE (data))
     len = GRUB_MINIX_INODE_SIZE (data) - pos;
+  if (len == 0)
+    return 0;
 
   /* Files are at most 2G/4G - 1 bytes on minixfs. Avoid 64-bit division.  */
-  blockcnt = ((grub_uint32_t) ((len + pos
-				+ (data->block_size << GRUB_DISK_SECTOR_BITS)
-				- 1)
-	       >> GRUB_DISK_SECTOR_BITS)) / data->block_size;
+  blockcnt = ((grub_uint32_t) ((len + pos - 1)
+	       >> GRUB_DISK_SECTOR_BITS)) / data->block_size + 1;
   posblock = (((grub_uint32_t) pos)
 	      / (data->block_size << GRUB_DISK_SECTOR_BITS));
   blockoff = (((grub_uint32_t) pos)
-- 
1.8.2.1