ShellPkg: Update CWD and current mapping when commands return

Some commands may cause current directory or even current mapping
become invalid. For example, "MAP" after unplugging the USB thumb
key may cause current mapping "FS0:" disappear.
This patch updates the CWD and current mapping when commands return.
It also causes the command prompt change to default "Shell>".

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Huajing Li <huajing.li@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by Jaben Carsey <jaben.carsey@intel.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/ShellPkg/Application/Shell/Shell.c b/ShellPkg/Application/Shell/Shell.c
index fcf47b5..5471930 100644
--- a/ShellPkg/Application/Shell/Shell.c
+++ b/ShellPkg/Application/Shell/Shell.c
@@ -2614,6 +2614,7 @@ RunShellCommand(
   CHAR16                    *FirstParameter;

   CHAR16                    *TempWalker;

   SHELL_OPERATION_TYPES     Type;

+  CONST CHAR16              *CurDir;

 

   ASSERT(CmdLine != NULL);

   if (StrLen(CmdLine) == 0) {

@@ -2705,7 +2706,22 @@ RunShellCommand(
     ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_SHELL_NOT_FOUND), ShellInfoObject.HiiHandle, FirstParameter);

     SetLastError(SHELL_NOT_FOUND);

   }

- 

+  //

+  // Check whether the current file system still exists. If not exist, we need update "cwd" and gShellCurMapping.

+  //

+  CurDir = EfiShellGetCurDir (NULL);

+  if (CurDir != NULL) {

+    if (EFI_ERROR(ShellFileExists (CurDir))) {

+      //

+      // EfiShellSetCurDir() cannot set current directory to NULL.

+      // EfiShellSetEnv() is not allowed to set the "cwd" variable.

+      // Only InternalEfiShellSetEnv () is allowed setting the "cwd" variable.

+      //

+      InternalEfiShellSetEnv (L"cwd", NULL, TRUE);

+      gShellCurMapping = NULL;

+    }

+  }

+

   SHELL_FREE_NON_NULL(CleanOriginal);

   SHELL_FREE_NON_NULL(FirstParameter);