dmstyle: IsParamSupported method doesn't crashes on NULL.

dlls/dmstyle/auditiontrack.c

@@ -144,6 +144,10 @@ static HRESULT WINAPI IDirectMusicAuditionTrack_IDirectMusicTrack_IsParamSupport
 	ICOM_THIS_MULTI(IDirectMusicAuditionTrack, TrackVtbl, iface);
 
 	TRACE("(%p, %s)\n", This, debugstr_dmguid(rguidType));
+
+        if (!rguidType)
+                return E_POINTER;
+
 	/* didn't find any params */
 	TRACE("param unsupported\n");
 	return DMUS_E_TYPE_UNSUPPORTED;

dlls/dmstyle/chordtrack.c

@@ -145,6 +145,10 @@ static HRESULT WINAPI IDirectMusicChordTrack_IDirectMusicTrack_IsParamSupported
   ICOM_THIS_MULTI(IDirectMusicChordTrack, TrackVtbl, iface);
   
   TRACE("(%p, %s)\n", This, debugstr_dmguid(rguidType));
+
+  if (!rguidType)
+    return E_POINTER;
+
   if (IsEqualGUID (rguidType, &GUID_BandParam)
       || IsEqualGUID (rguidType, &GUID_ChordParam)
       || IsEqualGUID (rguidType, &GUID_RhythmParam)) {

dlls/dmstyle/commandtrack.c

@@ -145,6 +145,10 @@ static HRESULT WINAPI IDirectMusicCommandTrack_IDirectMusicTrack_IsParamSupporte
 	ICOM_THIS_MULTI(IDirectMusicCommandTrack, TrackVtbl, iface);
 
 	TRACE("(%p, %s)\n", This, debugstr_dmguid(rguidType));
+
+        if (!rguidType)
+                return E_POINTER;
+
 	if (IsEqualGUID (rguidType, &GUID_CommandParam)
 		|| IsEqualGUID (rguidType, &GUID_CommandParam2)
 		|| IsEqualGUID (rguidType, &GUID_CommandParamNext)) {

dlls/dmstyle/motiftrack.c

@@ -144,6 +144,10 @@ static HRESULT WINAPI IDirectMusicMotifTrack_IDirectMusicTrack_IsParamSupported
 	ICOM_THIS_MULTI(IDirectMusicMotifTrack, TrackVtbl, iface);
 
 	TRACE("(%p, %s)\n", This, debugstr_dmguid(rguidType));
+
+        if (!rguidType)
+                return E_POINTER;
+
 	if (IsEqualGUID (rguidType, &GUID_DisableTimeSig)
 		|| IsEqualGUID (rguidType, &GUID_EnableTimeSig)
 		|| IsEqualGUID (rguidType, &GUID_SeedVariations)

dlls/dmstyle/mutetrack.c

@@ -144,6 +144,10 @@ static HRESULT WINAPI IDirectMusicMuteTrack_IDirectMusicTrack_IsParamSupported (
 	ICOM_THIS_MULTI(IDirectMusicMuteTrack, TrackVtbl, iface);
 
 	TRACE("(%p, %s)\n", This, debugstr_dmguid(rguidType));
+
+        if (!rguidType)
+                return E_POINTER;
+
 	if (IsEqualGUID (rguidType, &GUID_MuteParam)) {
 		TRACE("param supported\n");
 		return S_OK;

dlls/dmstyle/styletrack.c

@@ -145,6 +145,10 @@ static HRESULT WINAPI IDirectMusicStyleTrack_IDirectMusicTrack_IsParamSupported
 	ICOM_THIS_MULTI(IDirectMusicStyleTrack, TrackVtbl, iface);
 
 	TRACE("(%p, %s)\n", This, debugstr_dmguid(rguidType));
+
+        if (!rguidType)
+                return E_POINTER;
+
 	if (IsEqualGUID (rguidType, &GUID_DisableTimeSig)
 		|| IsEqualGUID (rguidType, &GUID_EnableTimeSig)
 		|| IsEqualGUID (rguidType, &GUID_IDirectMusicStyle)

dlls/dmstyle/tests/dmstyle.c

@@ -273,6 +273,10 @@ static void test_track(void)
         }
         ok(hr == S_OK, "%s create failed: %08x, expected S_OK\n", class[i].name, hr);
 
+        /* IDirectMusicTrack8 */
+        hr = IDirectMusicTrack8_IsParamSupported(dmt8, NULL);
+        ok(hr == E_POINTER, "IDirectMusicTrack8_IsParamSupported failed: %08x\n", hr);
+
         /* IPersistStream */
         hr = IDirectMusicTrack8_QueryInterface(dmt8, &IID_IPersistStream, (void**)&ps);
         ok(hr == S_OK, "QueryInterface for IID_IPersistStream failed: %08x\n", hr);