Re: [PATCH] MdeModulePkg/UdfDxe: Remove negative comparison of unsigned number

["Zeng, Star" <star.zeng@intel.com>]

I do not understand the context of the code.
The change is good to fix the build failure, but I want to ask a question before I gave Rb. :)

Is it possible ReadFileInfo->FilePosition less than FilePosition?


Thanks,
Star
-----Original Message-----
From: Paulo Alcantara [mailto:pcacjr@zytor.com] 
Sent: Wednesday, September 13, 2017 12:45 PM
To: edk2-devel@lists.01.org
Cc: Paulo Alcantara <pcacjr@zytor.com>; Zeng, Star <star.zeng@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>; Bi, Dandan <dandan.bi@intel.com>
Subject: [PATCH] MdeModulePkg/UdfDxe: Remove negative comparison of unsigned number

This patch gets rid of a negative comparison of an UINT64 type (Offset) as it'll never evaluate to true.

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Dandan Bi <dandan.bi@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Reported-by: Star Zeng <star.zeng@intel.com>
Signed-off-by: Paulo Alcantara <pcacjr@zytor.com>
---
 MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
index 7286265373..2039f80289 100644
--- a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
@@ -1082,9 +1082,6 @@ ReadFile (
 
         if (FilePosition + ExtentLength > ReadFileInfo->FilePosition) {
           Offset = ReadFileInfo->FilePosition - FilePosition;
-          if (Offset < 0) {
-            Offset = -(Offset);
-          }
         } else {
           Offset = 0;
         }
--
2.11.0