[PATCH] msdmo: Fix null deref in any_types_match.

[Patrick Hibbs]

Signed-off-by: Patrick Hibbs 
---
 dlls/msdmo/dmoreg.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/dlls/msdmo/dmoreg.c b/dlls/msdmo/dmoreg.c
index 8e0680931f4..42e4eab3651 100644
--- a/dlls/msdmo/dmoreg.c
+++ b/dlls/msdmo/dmoreg.c
@@ -451,10 +451,16 @@ static BOOL any_types_match(const DMO_PARTIAL_MEDIATYPE *a, unsigned int a_count

for (i = 0; i < a_count; ++i)
     {
-        for (j = 0; j < b_count; ++j)
+        if (a != NULL)
         {
-            if (IsMediaTypeEqual(&a[i], &b[j]))
-                return TRUE;
+            for (j = 0; j < b_count; ++j)
+            {
+                if (b != NULL)
+                {
+                    if (IsMediaTypeEqual(&a[i], &b[j]))
+                        return TRUE;
+                }
+            }
         }
     }
     return FALSE;