From 33eb033f8609d960ccf6c3ad9abb0acab5e1a08f Mon Sep 17 00:00:00 2001
From: Jaben Carsey <Jaben.carsey@intel.com>
Date: Thu, 5 Jun 2014 22:02:12 +0000
Subject: [PATCH] ShellPkg: fix Comp command output

The comp command was potentially displaying the incorrect offset into the file due to comparing 3 extra bytes for difference groups.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <Jaben.carsey@intel.com>
Reviewed-by: Tapan Shah <tapandshah@hp.com>
Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15558 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Library/UefiShellDebug1CommandsLib/Comp.c | 29 +++++++++++++------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/ShellPkg/Library/UefiShellDebug1CommandsLib/Comp.c b/ShellPkg/Library/UefiShellDebug1CommandsLib/Comp.c
index 01ef1997b2..f4e20a4e3a 100644
--- a/ShellPkg/Library/UefiShellDebug1CommandsLib/Comp.c
+++ b/ShellPkg/Library/UefiShellDebug1CommandsLib/Comp.c
@@ -1,7 +1,7 @@
 /** @file
   Main file for Comp shell Debug1 function.
 
-  Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2010 - 2014, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -50,6 +50,7 @@ ShellCommandRunComp (
   CHAR16              *FileName1;
   CHAR16              *FileName2;
   CONST CHAR16        *TempParam;
+  UINTN               ErrorAddress;
 
   ErrorCount          = 0;
   ShellStatus         = SHELL_SUCCESS;
@@ -136,12 +137,18 @@ ShellCommandRunComp (
           Status = gEfiShellProtocol->ReadFile(FileHandle2, &DataSizeFromFile2, &DataFromFile2);
           ASSERT_EFI_ERROR(Status);
           if (DataFromFile1 != DataFromFile2) {
+            ErrorAddress = LoopVar;
             ADF_File11 = 0;
             ADF_File12 = 0;
             ADF_File13 = 0;
             ADF_File21 = 0;
             ADF_File22 = 0;
             ADF_File23 = 0;
+
+            //
+            // Now check the next 3 bytes if possible.  This will make output
+            // cleaner when there are a sequence of differences.
+            //
             if (LoopVar + 1 < Size1) {
               LoopVar++;
               DataSizeFromFile1 = 1;
@@ -169,6 +176,10 @@ ShellCommandRunComp (
                 }
               }
             }
+
+            //
+            // Print out based on highest of the 4 bytes that are different.
+            //
             if (ADF_File13 != ADF_File23) {
               ShellPrintHiiEx(
                 -1,
@@ -178,11 +189,11 @@ ShellCommandRunComp (
                 gShellDebug1HiiHandle,
                 ++ErrorCount,
                 FileName1,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile1, ADF_File11, ADF_File12, ADF_File13,
                 DataFromFile1, ADF_File11, ADF_File12, ADF_File13,
                 FileName2,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile2, ADF_File21, ADF_File22, ADF_File23,
                 DataFromFile2, ADF_File21, ADF_File22, ADF_File23
                );
@@ -195,11 +206,11 @@ ShellCommandRunComp (
                 gShellDebug1HiiHandle,
                 ++ErrorCount,
                 FileName1,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile1, ADF_File11, ADF_File12,
                 DataFromFile1, ADF_File11, ADF_File12,
                 FileName2,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile2, ADF_File21, ADF_File22,
                 DataFromFile2, ADF_File21, ADF_File22
                );
@@ -212,11 +223,11 @@ ShellCommandRunComp (
                 gShellDebug1HiiHandle,
                 ++ErrorCount,
                 FileName1,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile1, ADF_File11,
                 DataFromFile1, ADF_File11,
                 FileName2,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile2, ADF_File21,
                 DataFromFile2, ADF_File21
                );
@@ -229,11 +240,11 @@ ShellCommandRunComp (
                 gShellDebug1HiiHandle,
                 ++ErrorCount,
                 FileName1,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile1,
                 DataFromFile1,
                 FileName2,
-                LoopVar,
+                ErrorAddress,
                 DataFromFile2,
                 DataFromFile2
                );
-- 
2.39.2