Function simplifyPath

externals/simplecpp/simplecpp.cpp:2529–2597

* perform path simplifications for . and .. */

     * perform path simplifications for . and ..
     */
    std::string simplifyPath(std::string path)
    {
        if (path.empty())
            return path;

        std::string::size_type pos;

        // replace backslash separators
        std::replace(path.begin(), path.end(), '\\', '/');

        const bool unc(path.compare(0,2,"//") == 0);

        // replace "//" with "/"
        pos = 0;
        while ((pos = path.find("//",pos)) != std::string::npos) {
            path.erase(pos,1);
        }

        // remove "./"
        pos = 0;
        while ((pos = path.find("./",pos)) != std::string::npos) {
            if (pos == 0 || path[pos - 1U] == '/')
                path.erase(pos,2);
            else
                pos += 2;
        }

        // remove trailing dot if path ends with "/."
        if (endsWith(path,"/."))
            path.erase(path.size()-1);

        // simplify ".."
        pos = 1; // don't simplify ".." if path starts with that
        while ((pos = path.find("/..", pos)) != std::string::npos) {
            // not end of path, then string must be "/../"
            if (pos + 3 < path.size() && path[pos + 3] != '/') {
                ++pos;
                continue;
            }
            // get previous subpath
            std::string::size_type pos1 = path.rfind('/', pos - 1U);
            if (pos1 == std::string::npos) {
                pos1 = 0;
            } else {
                pos1 += 1U;
            }
            const std::string previousSubPath = path.substr(pos1, pos - pos1);
            if (previousSubPath == "..") {
                // don't simplify
                ++pos;
            } else {
                // remove previous subpath and ".."
                path.erase(pos1, pos - pos1 + 4);
                if (path.empty())
                    path = ".";
                // update pos
                pos = (pos1 == 0) ? 1 : (pos1 - 1);
            }