[PATCH] ShellPkg/UefiShellLib: Set input pointer parameter to null if failure

["Gao, Zhichao" <zhichao.gao@intel.com>]

From: Bret Barkelew <Bret.Barkelew@microsoft.com>

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1906

While failed to allocate memory to save the response,
set the input/output parameter 'Response'(VOID **) to
NULL to indicate the failure not only depend on the
returned status.

Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
---
 ShellPkg/Library/UefiShellLib/UefiShellLib.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ShellPkg/Library/UefiShellLib/UefiShellLib.c b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
index 430b20e127..5be530092e 100644
--- a/ShellPkg/Library/UefiShellLib/UefiShellLib.c
+++ b/ShellPkg/Library/UefiShellLib/UefiShellLib.c
@@ -3366,6 +3366,9 @@ ShellPromptForResponse (
   if (Type != ShellPromptResponseTypeFreeform) {
     Resp = (SHELL_PROMPT_RESPONSE*)AllocateZeroPool(sizeof(SHELL_PROMPT_RESPONSE));
     if (Resp == NULL) {
+      if (Response != NULL) {
+        *Response = NULL;
+      }
       return (EFI_OUT_OF_RESOURCES);
     }
   }
@@ -3568,6 +3571,8 @@ ShellPromptForResponse (
       *Response = Resp;
     } else if (Buffer != NULL) {
       *Response = Buffer;
+    } else {
+      *Response = NULL;
     }
   } else {
     if (Resp != NULL) {
-- 
2.21.0.windows.1