Коротко. Вопрос. Что делает код и что в нём не так?

    typedef std::list<TagFilterElem> TagChildrenForPrune;
    
    void pruneEmpty(TagChildrenForPrune & aTagChildren, TagChildrenForPrune::iterator & aLastContainer)
    {
        if (aLastContainer != aTagChildren.end()) {
            for (auto vIt = aLastContainer->rTagValue.rChildren.rbegin(); vIt != aLastContainer->rTagValue.rChildren.rend(); /*vIt++*/) {
                if (!vIt->is_type_of(evd::id_TextPara))
                    break;
                if (DocumentFilter::ChildHasText(*vIt))
                    break;
                aLastContainer->rTagValue.rChildren.erase(--aLastContainer->rTagValue.rChildren.end());
                vIt = aLastContainer->rTagValue.rChildren.rbegin();
            }
            if (aLastContainer->rTagValue.rChildren.size() == 0) {
                aTagChildren.erase(aLastContainer);
            }
        }
        aLastContainer = aTagChildren.end();
    }
    
    void PlainBlock (BlockStack::reference aChild)
    {
        if (aChild.is_type_of(evd::id_ContentsElement) || aChild.is_type_of(evd::id_Table)) {
            for (auto & vChild : aChild.rTagValue.rChildren) {
                PlainBlock(vChild);
            }
            if (IsMixed(aChild)) {
//                TagFilterElem::ElemData::TagChildren vTagChildren;
                TagChildrenForPrune vTagChildren;
                auto vLastContainer = vTagChildren.end();
                auto vFlagsIt = aChild.rTagValue.rTags.find(evd::ti_Flags);
                for (auto & vChild : aChild.rTagValue.rChildren) {
                    if (vChild.is_type_of(evd::id_ContentsElement)) {
                        pruneEmpty(vTagChildren, vLastContainer);
                        vTagChildren.push_back(vChild);
                    }
                    else
//                    if (vChild.is_leaf_para())
                    {
                        if (vLastContainer == vTagChildren.end()) {
                            TagFilterElem vContainer (evd::id_Block);
                            if (vFlagsIt != aChild.rTagValue.rTags.end()) {
                                vContainer.rTagValue.rTags.insert(*vFlagsIt);
                                long vFlags = vFlagsIt->second.IntValue() & ~(long)MASK_NEW_PAGE;
                                if (vFlags)
                                    vFlagsIt->second = vFlags;
                                else
                                    aChild.rTagValue.rTags.erase(vFlagsIt);
                                vFlagsIt = aChild.rTagValue.rTags.end();
                            }
                            vTagChildren.push_back(vContainer);
                            vLastContainer = --vTagChildren.end();
                        }
                        vLastContainer->rTagValue.rChildren.push_back(vChild);
                    }
//                    else
//                        ASSERT_NO_MSG(false);
                }
                pruneEmpty(vTagChildren, vLastContainer);
                aChild.rTagValue.rChildren.clear();
                aChild.rTagValue.rChildren.insert(aChild.rTagValue.rChildren.begin(), vTagChildren.begin(), vTagChildren.end());
                ASSERT_NO_MSG(!IsMixed(aChild));
            }
        }
    }