d3dx9: Fix the case output = input in D3DXVec3Cross.

dlls/d3dx9_36/tests/math.c

@@ -1251,6 +1251,9 @@ static void D3DXVector3Test(void)
     expectedvec.x = -18.0f; expectedvec.y = 40.0f; expectedvec.z = -39.0f;
     D3DXVec3Cross(&gotvec,&u,&v);
     expect_vec3(expectedvec,gotvec);
+    expectedvec.x = -277.0f; expectedvec.y = -150.0f; expectedvec.z = -26.0f;
+    D3DXVec3Cross(&gotvec,&gotvec,&v);
+    expect_vec3(expectedvec,gotvec);
     /* Tests the case NULL */
     funcpointer = D3DXVec3Cross(&gotvec,NULL,&v);
     ok(funcpointer == NULL, "Expected: %p, Got: %p\n", NULL, funcpointer);

include/d3dx9math.inl

@@ -1029,10 +1029,13 @@ static inline D3DXVECTOR3* D3DXVec3Add(D3DXVECTOR3 *pout, CONST D3DXVECTOR3 *pv1
 
 static inline D3DXVECTOR3* D3DXVec3Cross(D3DXVECTOR3 *pout, CONST D3DXVECTOR3 *pv1, CONST D3DXVECTOR3 *pv2)
 {
+    D3DXVECTOR3 temp;
+
     if ( !pout || !pv1 || !pv2) return NULL;
-    pout->x = (pv1->y) * (pv2->z) - (pv1->z) * (pv2->y);
-    pout->y = (pv1->z) * (pv2->x) - (pv1->x) * (pv2->z);
-    pout->z = (pv1->x) * (pv2->y) - (pv1->y) * (pv2->x);
+    temp.x = (pv1->y) * (pv2->z) - (pv1->z) * (pv2->y);
+    temp.y = (pv1->z) * (pv2->x) - (pv1->x) * (pv2->z);
+    temp.z = (pv1->x) * (pv2->y) - (pv1->y) * (pv2->x);
+    *pout = temp;
     return pout;
 }