d2d1: Silently ignore non-default state block implementations.

dlls/d2d1/device.c

@@ -1735,11 +1735,12 @@ static HRESULT STDMETHODCALLTYPE d2d_device_context_Flush(ID2D1DeviceContext1 *i
 static void STDMETHODCALLTYPE d2d_device_context_SaveDrawingState(ID2D1DeviceContext1 *iface,
         ID2D1DrawingStateBlock *state_block)
 {
-    struct d2d_state_block *state_block_impl = unsafe_impl_from_ID2D1DrawingStateBlock(state_block);
     struct d2d_device_context *render_target = impl_from_ID2D1DeviceContext(iface);
+    struct d2d_state_block *state_block_impl;
 
     TRACE("iface %p, state_block %p.\n", iface, state_block);
 
+    if (!(state_block_impl = unsafe_impl_from_ID2D1DrawingStateBlock(state_block))) return;
     state_block_impl->drawing_state = render_target->drawing_state;
     if (render_target->text_rendering_params)
         IDWriteRenderingParams_AddRef(render_target->text_rendering_params);
@@ -1751,11 +1752,12 @@ static void STDMETHODCALLTYPE d2d_device_context_SaveDrawingState(ID2D1DeviceCon
 static void STDMETHODCALLTYPE d2d_device_context_RestoreDrawingState(ID2D1DeviceContext1 *iface,
         ID2D1DrawingStateBlock *state_block)
 {
-    struct d2d_state_block *state_block_impl = unsafe_impl_from_ID2D1DrawingStateBlock(state_block);
     struct d2d_device_context *context = impl_from_ID2D1DeviceContext(iface);
+    struct d2d_state_block *state_block_impl;
 
     TRACE("iface %p, state_block %p.\n", iface, state_block);
 
+    if (!(state_block_impl = unsafe_impl_from_ID2D1DrawingStateBlock(state_block))) return;
     if (context->target.type == D2D_TARGET_COMMAND_LIST)
     {
         struct d2d_command_list *command_list = context->target.command_list;

dlls/d2d1/state_block.c

@@ -186,6 +186,10 @@ struct d2d_state_block *unsafe_impl_from_ID2D1DrawingStateBlock(ID2D1DrawingStat
 {
     if (!iface)
         return NULL;
-    assert(iface->lpVtbl == (ID2D1DrawingStateBlockVtbl *)&d2d_state_block_vtbl);
+    if (iface->lpVtbl != (ID2D1DrawingStateBlockVtbl *)&d2d_state_block_vtbl)
+    {
+        WARN("Unexpected state block vtbl %p.\n", iface->lpVtbl);
+        return NULL;
+    }
     return CONTAINING_RECORD(iface, struct d2d_state_block, ID2D1DrawingStateBlock1_iface);
 }

dlls/d2d1/tests/d2d1.c

@@ -1835,6 +1835,7 @@ static void test_state_block(BOOL d3d11)
     ID2D1Factory *factory;
     ULONG refcount;
     HRESULT hr;
+    void *ptr;
     static const D2D1_MATRIX_3X2_F identity =
     {{{
         1.0f, 0.0f,
@@ -2078,6 +2079,15 @@ static void test_state_block(BOOL d3d11)
 
     refcount = IDWriteRenderingParams_Release(text_rendering_params1);
     ok(!refcount, "Rendering params %lu references left.\n", refcount);
+
+    /* State block object pointer is validated, but does not result in an error state. */
+    ptr = (void *)0xdeadbeef;
+    ID2D1RenderTarget_BeginDraw(rt);
+    ID2D1RenderTarget_SaveDrawingState(rt, (ID2D1DrawingStateBlock *)&ptr);
+    ID2D1RenderTarget_RestoreDrawingState(rt, (ID2D1DrawingStateBlock *)&ptr);
+    hr = ID2D1RenderTarget_EndDraw(rt, NULL, NULL);
+    ok(hr == S_OK, "Got unexpected hr %#lx.\n", hr);
+
     release_test_context(&ctx);
 }