Fix for ImGui::SetActiveID in imgui.cpp

imgui.cpp

@@ -3835,12 +3835,15 @@ void ImGui::SetActiveID(ImGuiID id, ImGuiWindow* window)
 {
     ImGuiContext& g = *GImGui;
 
-
-    for (int i = 0; i < DC.Layouts.Data.Size; i++)
+    if (window != NULL)
     {
-        ImGuiLayout* layout = (ImGuiLayout*)DC.Layouts.Data[i].val_p;
-        IM_DELETE(layout);
+        for (int i = 0; i < window->DC.Layouts.Data.Size; i++)
+        {
+            ImGuiLayout* layout = (ImGuiLayout*)window->DC.Layouts.Data[i].val_p;
+            IM_DELETE(layout);
+        }
     }
+
     // While most behaved code would make an effort to not steal active id during window move/drag operations,
     // we at least need to be resilient to it. Cancelling the move is rather aggressive and users of 'master' branch
     // may prefer the weird ill-defined half working situation ('docking' did assert), so may need to rework that.