test

        // attributes, so the legacy attribute drops out of the file on save).

        inline void splitSpacingShorthand(const std::string &value, std::string &top,

                                           std::string &right, std::string &bottom, std::string &left) {

            // Split on whitespace, but not while inside an unbalanced '(' --

            // a single shorthand value is very commonly itself a function

            // call containing spaces (e.g. "calc(120px / 2) calc(120px / 2)"

            // is a valid 2-value shorthand, each side its own calc()).

            // istringstream's operator>> splits on every space regardless,

            // which shreds each calc() into several bogus fragments (here,

            // 6 "tokens" instead of 2) and silently corrupts the resulting

            // per-side values into invalid CSS.

            std::vector<std::string> parts;

            std::istringstream iss(value);

            std::string tok;

            while (iss >> tok) parts.push_back(tok);

            std::string cur;

            int depth = 0;

            for (char c : value) {

                if (c == '(') { ++depth; cur += c; }

                else if (c == ')') { if (depth > 0) --depth; cur += c; }

                else if (depth == 0 && std::isspace(static_cast<unsigned char>(c))) {

                    if (!cur.empty()) { parts.push_back(cur); cur.clear(); }

                } else {

                    cur += c;

                }

            }

            if (!cur.empty()) parts.push_back(cur);

            if (parts.empty()) return;

            switch (parts.size()) {

                case 1: top = right = bottom = left = parts[0]; break;