1 files changed, 12 insertions, 4 deletions

diff --git a/src/dutil/verutil.cpp b/src/dutil/verutil.cpp
index 835dde81..fdb5a10a 100644
--- a/src/dutil/verutil.cpp
+++ b/src/dutil/verutil.cpp
@@ -40,8 +40,8 @@ static HRESULT CompareVersionSubstring(
 
 
 DAPI_(HRESULT) VerCompareParsedVersions(
-    __in VERUTIL_VERSION* pVersion1,
-    __in VERUTIL_VERSION* pVersion2,
+    __in_opt VERUTIL_VERSION* pVersion1,
+    __in_opt VERUTIL_VERSION* pVersion2,
     __out int* pnResult
     )
 {
@@ -50,8 +50,8 @@ DAPI_(HRESULT) VerCompareParsedVersions(
     DWORD cMaxReleaseLabels = 0;
     BOOL fCompareMetadata = FALSE;
 
-    if (!pVersion1 || !pVersion1->sczVersion ||
-        !pVersion2 || !pVersion2->sczVersion)
+    if (pVersion1 && !pVersion1->sczVersion ||
+        pVersion2 && !pVersion2->sczVersion)
     {
         ExitFunction1(hr = E_INVALIDARG);
     }
@@ -60,6 +60,14 @@ DAPI_(HRESULT) VerCompareParsedVersions(
     {
         ExitFunction1(nResult = 0);
     }
+    else if (pVersion1 && !pVersion2)
+    {
+        ExitFunction1(nResult = 1);
+    }
+    else if (!pVersion1 && pVersion2)
+    {
+        ExitFunction1(nResult = -1);
+    }
 
     nResult = CompareDword(pVersion1->dwMajor, pVersion2->dwMajor);
     if (0 != nResult)