quartz: Validate input for IFilterGraph_FindFilterByName.

dlls/quartz/filtergraph.c

@@ -483,7 +483,8 @@ static HRESULT WINAPI GraphBuilder_FindFilterByName(IGraphBuilder *iface,
 
     TRACE("(%p/%p)->(%s (%p), %p)\n", This, iface, debugstr_w(pName), pName, ppFilter);
 
-    *ppFilter = NULL;
+    if (!ppFilter)
+        return E_POINTER;
 
     for (i = 0; i < This->nFilters; i++)
     {
@@ -495,6 +496,7 @@ static HRESULT WINAPI GraphBuilder_FindFilterByName(IGraphBuilder *iface,
         }
     }
 
+    *ppFilter = NULL;
     return VFW_E_NOT_FOUND;
 }
 

dlls/quartz/tests/filtergraph.c

@@ -143,6 +143,8 @@ static void test_graph_builder(void)
     hr = IGraphBuilder_FindFilterByName(pgraph, testFilterW, &pF2);
     ok(hr == S_OK, "IGraphBuilder_FindFilterByName returned %x\n", hr);
     ok(pF2 != NULL, "IGraphBuilder_FindFilterByName returned NULL\n");
+    hr = IGraphBuilder_FindFilterByName(pgraph, testFilterW, NULL);
+    ok(hr == E_POINTER, "IGraphBuilder_FindFilterByName returned %x\n", hr);
     releasefiltergraph();
 }