ShellPkg: Add checks for NULL pointers.

This adds lots of pointer verification with ASSERTs only used when the condition should be impossible and never for memory allocation.

signed-off-by: jcarsey
reviewed-by: geekboy15a


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12524 6f19259b-4bc3-4df7-8a09-765794883524

ShellPkg/Library/UefiShellDebug1CommandsLib/HexEdit/HexEdit.c

@@ -189,7 +189,7 @@ ShellCommandRunHexEdit (
         switch (WhatToDo) {
         case FileTypeFileBuffer:
           Status = HBufferImageRead (
-                    Name,
+                    Name==NULL?L"":Name,
                     NULL,
                     0,
                     0,
@@ -203,7 +203,7 @@ ShellCommandRunHexEdit (
         case FileTypeDiskBuffer:
           Status = HBufferImageRead (
                     NULL,
-                    Name,
+                    Name==NULL?L"":Name,
                     Offset,
                     Size,
                     0,