Re: [PATCH] ShellPkg: Fix erroneous Status returned by ShellOpenFileByName()

["Shah, Tapan" <tapandshah@hpe.com>]

Reviewed-by: Tapan Shah <tapandshah@hpe.com>


-----Original Message-----
From: Vladimir Olovyannikov [mailto:vladimir.olovyannikov@broadcom.com] 
Sent: Thursday, October 06, 2016 5:02 PM
To: edk2-devel@lists.01.org; Shah, Tapan <tapandshah@hpe.com>; jaben.carsey@intel.com
Cc: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Subject: [PATCH] ShellPkg: Fix erroneous Status returned by ShellOpenFileByName()

In ShellOpenFileByName() the file is opened using
gEfiShellProtocol->OpenFileByName().
It is supposed that if this call returns an EFI_ERROR, the function should return that error immediately. However, this return was missing, and if UnicodeCollationProtocol has not been located by this time, the Status gets overwritten with LocateProtocol() call result, which eventually erroneously returns EFI_SUCCESS to the Shell.c, and this leads to attempt to execute a non-existent startup script, which fails, and which in turn leads to Shell being unloaded with "Invalid parameter"
error. This patch fixes the bug.

Cc: Tapan Shah <tapandshah@hpe.com>
Cc: Jaben Carsey <jaben.carsey@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
---
 ShellPkg/Library/UefiShellLib/UefiShellLib.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ShellPkg/Library/UefiShellLib/UefiShellLib.c b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
index 53f54e1746d4..8db18b3b210f 100644
--- a/ShellPkg/Library/UefiShellLib/UefiShellLib.c
+++ b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
@@ -723,6 +723,9 @@ ShellOpenFileByName(
     Status = gEfiShellProtocol->OpenFileByName(FileName,
                                                FileHandle,
                                                OpenMode);
+    if (EFI_ERROR(Status)) {
+      return Status;
+    }
 
     if (mUnicodeCollationProtocol == NULL) {
       Status = gBS->LocateProtocol (&gEfiUnicodeCollation2ProtocolGuid, NULL, (VOID**)&mUnicodeCollationProtocol);
--
1.9.1