From 8218518695ed8378aed4dd08953f708b9e29b06d Mon Sep 17 00:00:00 2001
From: Paul Vriens <Paul.Vriens.Wine@gmail.com>
Date: Thu, 29 Jan 2009 13:32:59 +0100
Subject: [PATCH] crypt32: Fix CertDuplicateCertificateContext for a passed
 NULL context.

---
 dlls/crypt32/cert.c       |  4 ++++
 dlls/crypt32/tests/cert.c | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/dlls/crypt32/cert.c b/dlls/crypt32/cert.c
index c6775561254..2780cba6343 100644
--- a/dlls/crypt32/cert.c
+++ b/dlls/crypt32/cert.c
@@ -115,6 +115,10 @@ PCCERT_CONTEXT WINAPI CertDuplicateCertificateContext(
  PCCERT_CONTEXT pCertContext)
 {
     TRACE("(%p)\n", pCertContext);
+
+    if (!pCertContext)
+        return NULL;
+
     Context_AddRef((void *)pCertContext, sizeof(CERT_CONTEXT));
     return pCertContext;
 }
diff --git a/dlls/crypt32/tests/cert.c b/dlls/crypt32/tests/cert.c
index e66b62101bc..844fd28903b 100644
--- a/dlls/crypt32/tests/cert.c
+++ b/dlls/crypt32/tests/cert.c
@@ -3136,6 +3136,16 @@ static void testGetPublicKeyLength(void)
     ok(ret == 56, "Expected length 56, got %d\n", ret);
 }
 
+static void testCertDuplicateCertificateContext(void)
+{
+    PCCERT_CONTEXT context;
+
+    SetLastError(0xdeadbeef);
+    context = CertDuplicateCertificateContext(NULL);
+    ok(context == NULL, "Expected context to be NULL\n");
+}
+
+
 START_TEST(cert)
 {
     init_function_pointers();
@@ -3163,4 +3173,5 @@ START_TEST(cert)
     testVerifyRevocation();
     testAcquireCertPrivateKey();
     testGetPublicKeyLength();
+    testCertDuplicateCertificateContext();
 }