ShellPkg: Fix the incorrect behavior when pressing 'shift' key.

If 'ReadKeyStroke' function return EFI_NOT_READY then skip it.
If the return value is EFI_DEVICE_ERROR clean the currentString buffer.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Pedroa Liu <pedroa.liu@insyde.com>
Reviewed-by: Qiu Shumin <shumin.qiu@intel.com>

diff --git a/ShellPkg/Application/Shell/FileHandleWrappers.c b/ShellPkg/Application/Shell/FileHandleWrappers.c
index 0e5efe30255631f36b972715c49a464970f88677..f64915d9ed33f2501cd75ee268c166dbb8779872 100644 (file)
--- a/ShellPkg/Application/Shell/FileHandleWrappers.c
+++ b/ShellPkg/Application/Shell/FileHandleWrappers.c
@@ -422,6 +422,12 @@ FileInterfaceStdInRead(
     gBS->WaitForEvent (1, &gST->ConIn->WaitForKey, &EventIndex);\r
     Status = gST->ConIn->ReadKeyStroke (gST->ConIn, &Key);\r
     if (EFI_ERROR (Status)) {\r
+\r
+      if (Status == EFI_NOT_READY)\r
+        continue;\r
+\r
+      ZeroMem (CurrentString, MaxStr * sizeof(CHAR16));\r
+      StringLen = 0;\r
       break;\r
     }\r
 \r