[PATCH] MdePkg/UefiFileHandleLib: Refine the check for valid Ascii character

[Hao Wu <hao.a.wu@intel.com>]

The commit will check if bit 7 is set of an Ascii character to judge its
validity.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c b/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
index daed0f4..57aad77 100644
--- a/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
+++ b/MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.c
@@ -1,7 +1,7 @@
 /** @file
   Provides interface to EFI_FILE_HANDLE functionality.
 
-  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved. <BR>
+  Copyright (c) 2006 - 2017, 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
@@ -1138,7 +1138,7 @@ FileHandleWriteLine(
     }
     UnicodeStrToAsciiStrS (Buffer, AsciiBuffer, Size);
     for (Index = 0; Index < Size; Index++) {
-      if (!((AsciiBuffer[Index] >= 0) && (AsciiBuffer[Index] < 128))){
+      if ((AsciiBuffer[Index] & BIT7) != 0) {
         FreePool(AsciiBuffer);
         return EFI_INVALID_PARAMETER;
       }
-- 
1.9.5.msysgit.0