Demo: fix in 'Demo->Selection->Multi-Select in a Table' section.

Author: ocornut

imgui_demo.cpp

@@ -2863,7 +2863,7 @@ static void DemoWindowWidgetsSelectionAndMultiSelect(ImGuiDemoWindowData* demo_d
 
             const int ITEMS_COUNT = 10000;
             ImGui::Text("Selection: %d/%d", selection.Size, ITEMS_COUNT);
-            if (ImGui::BeginTable("##Basket", 2, ImGuiTableFlags_ScrollY | ImGuiTableFlags_RowBg | ImGuiTableFlags_BordersOuter))
+            if (ImGui::BeginTable("##Basket", 2, ImGuiTableFlags_ScrollY | ImGuiTableFlags_RowBg | ImGuiTableFlags_BordersOuter, ImVec2(0.0f, ImGui::GetFontSize() * 20)))
             {
                 ImGui::TableSetupColumn("Object");
                 ImGui::TableSetupColumn("Action");
@@ -2884,13 +2884,15 @@ static void DemoWindowWidgetsSelectionAndMultiSelect(ImGuiDemoWindowData* demo_d
                     {
                         ImGui::TableNextRow();
                         ImGui::TableNextColumn();
+                        ImGui::PushID(n);
                         char label[64];
                         sprintf(label, "Object %05d: %s", n, ExampleNames[n % IM_ARRAYSIZE(ExampleNames)]);
                         bool item_is_selected = selection.Contains((ImGuiID)n);
                         ImGui::SetNextItemSelectionUserData(n);
                         ImGui::Selectable(label, item_is_selected, ImGuiSelectableFlags_SpanAllColumns | ImGuiSelectableFlags_AllowOverlap);
                         ImGui::TableNextColumn();
                         ImGui::SmallButton("hello");
+                        ImGui::PopID();
                     }
                 }