[d3d8] Validate viewport dimensions on SetViewport

src/d3d8/d3d8_device.cpp

@@ -926,6 +926,31 @@ namespace dxvk {
   }
 
   HRESULT STDMETHODCALLTYPE D3D8Device::SetViewport(const D3DVIEWPORT8* pViewport) {
+    if (likely(pViewport != nullptr)) {
+      HRESULT res;
+
+      // get the D3D9 render target if we haven't cached it yet
+      if (unlikely(m_renderTarget == nullptr)) {
+        Com<d3d9::IDirect3DSurface9> pRT9 = nullptr;
+        res = GetD3D9()->GetRenderTarget(0, &pRT9); // use RT index 0
+
+        if (likely(SUCCEEDED(res)))
+          m_renderTarget = new D3D8Surface(this, std::move(pRT9));
+      }
+
+      if (likely(m_renderTarget != nullptr)) {
+        D3DSURFACE_DESC rtDesc;
+        res = m_renderTarget->GetDesc(&rtDesc);
+
+        // D3D8 will fail when setting a viewport that's outside of the
+        // current render target, although this apparently works in D3D9
+        if (likely(SUCCEEDED(res)) &&
+            unlikely(pViewport->Width  > rtDesc.Width ||
+                     pViewport->Height > rtDesc.Height))
+          return D3DERR_INVALIDCALL;
+      }
+    }
+
     StateChange();
     return GetD3D9()->SetViewport(reinterpret_cast<const d3d9::D3DVIEWPORT9*>(pViewport));
   }