Tables: storing LastFrozenHeight for frozen requests that don't have actual freezing due to zero scrolling. (#7821, #5143)

Amend 0b4a1a40
(ignore whitespace to view this patch easily)

imgui_tables.cpp

@@ -1996,14 +1996,16 @@ void ImGui::TableEndRow(ImGuiTable* table)
     // We need to do that in TableEndRow() instead of TableBeginRow() so the list clipper can mark end of row and
     // get the new cursor position.
     if (unfreeze_rows_request)
+    {
         for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
             table->Columns[column_n].NavLayerCurrent = ImGuiNavLayer_Main;
+        const float y0 = ImMax(table->RowPosY2 + 1, window->InnerClipRect.Min.y);
+        table_instance->LastFrozenHeight = y0 - table->OuterRect.Min.y;
+
         if (unfreeze_rows_actual)
         {
             IM_ASSERT(table->IsUnfrozenRows == false);
-        const float y0 = ImMax(table->RowPosY2 + 1, window->InnerClipRect.Min.y);
             table->IsUnfrozenRows = true;
-        table_instance->LastFrozenHeight = y0 - table->OuterRect.Min.y;
 
             // BgClipRect starts as table->InnerClipRect, reduce it now and make BgClipRectForDrawCmd == BgClipRect
             table->BgClipRect.Min.y = table->Bg2ClipRectForDrawCmd.Min.y = ImMin(y0, window->InnerClipRect.Max.y);
@@ -2025,6 +2027,7 @@ void ImGui::TableEndRow(ImGuiTable* table)
             SetWindowClipRectBeforeSetChannel(window, table->Columns[0].ClipRect);
             table->DrawSplitter->SetCurrentChannel(window->DrawList, table->Columns[0].DrawChannelCurrent);
         }
+    }
 
     if (!(table->RowFlags & ImGuiTableRowFlags_Headers))
         table->RowBgColorCounter++;