From 053d95e7e5e37378f6b21fe19009423762be894f Mon Sep 17 00:00:00 2001
From: Star Zeng <star.zeng@intel.com>
Date: Fri, 13 May 2016 13:01:28 +0800
Subject: [PATCH] DuetPkg FSVariable: return error for empty str VariableName
 to GetVariable

Current GetVariable implementation will return the first variable for
empty str VariableName, it is because GetVariable and GetNextVariablename
are sharing same function FindVariable.
But UEFI sepc defines SetVariable that If VariableName is an empty string,
then EFI_INVALID_PARAMETER is returned, that means an empty string variable
could never be set successfully, so GetVariable should return error for
empty string VariableName.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
---
 DuetPkg/FSVariable/FSVariable.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/DuetPkg/FSVariable/FSVariable.c b/DuetPkg/FSVariable/FSVariable.c
index 06df161e5d..34b79305c8 100644
--- a/DuetPkg/FSVariable/FSVariable.c
+++ b/DuetPkg/FSVariable/FSVariable.c
@@ -1337,6 +1337,10 @@ Returns:
     return EFI_INVALID_PARAMETER;
   }
 
+  if (VariableName[0] == 0) {
+    return EFI_NOT_FOUND;
+  }
+
   //
   // Find existing variable
   //