diff --git a/src/core/dataprotocol.cpp b/src/core/dataprotocol.cpp
index bd06920b..175acd66 100644
--- a/src/core/dataprotocol.cpp
+++ b/src/core/dataprotocol.cpp
@@ -1,328 +1,325 @@
 //  dataprotocol.cpp
 // ==================
 //
 // Implementation of the data protocol (rfc 2397)
 //
 // Author: Leo Savernik
 // Email: l.savernik@aon.at
 // Copyright (C) 2002, 2003 by Leo Savernik <l.savernik@aon.at>
 // Created: Sam Dez 28 14:11:18 CET 2002
 
 /***************************************************************************
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU Lesser General Public License as        *
  *   published by the Free Software Foundation; version 2.                 *
  *                                                                         *
  ***************************************************************************/
 
-// TODO: remove me
-#undef QT_NO_CAST_FROM_ASCII
-
 #include "dataprotocol_p.h"
 
 #include "global.h"
 
 #include <QByteArray>
 #include <QCharRef>
 #include <QTextCodec>
 
 #ifdef DATAKIOSLAVE
 #  include <kinstance.h>
 #  include <stdlib.h>
 #endif
 
 #if !defined(DATAKIOSLAVE)
 #  define DISPATCH(f) dispatch_##f
 #else
 #  define DISPATCH(f) f
 #endif
 
 using namespace KIO;
 #ifdef DATAKIOSLAVE
 extern "C" {
 
     int kdemain(int argc, char **argv)
     {
         //qDebug() << "*** Starting kio_data ";
 
         if (argc != 4) {
             //qDebug() << "Usage: kio_data  protocol domain-socket1 domain-socket2";
             exit(-1);
         }
 
         DataProtocol slave(argv[2], argv[3]);
         slave.dispatchLoop();
 
         //qDebug() << "*** kio_data Done";
         return 0;
     }
 }
 #endif
 
 /** structure containing header information */
 struct DataHeader {
     QString mime_type;        // mime type of content (lowercase)
     MetaData attributes;      // attribute/value pairs (attribute lowercase,
     //  value unchanged)
     bool is_base64;       // true if data is base64 encoded
     QByteArray url;       // reference to decoded url
     int data_offset;      // zero-indexed position within url
     // where the real data begins. May point beyond
     // the end to indicate that there is no data
 };
 
 /** returns the position of the first occurrence of any of the given
   * characters @p c1 or comma (',') or semicolon (';') or buf.length()
   * if none is contained.
   *
   * @param buf buffer where to look for c
   * @param begin zero-indexed starting position
   * @param c1 character to find or '\0' to ignore
   */
 static int find(const QByteArray &buf, int begin, const char c1)
 {
     static const char comma = ',';
     static const char semicolon = ';';
     int pos = begin;
     int size = buf.length();
     while (pos < size) {
         const char ch = buf[pos];
         if (ch == comma || ch == semicolon || (c1 != '\0' && ch == c1)) {
             break;
         }
         pos++;
     }/*wend*/
     return pos;
 }
 
 /** extracts the string between the current position @p pos and the first
  * occurrence of either @p c1 or comma (',') or semicolon (';') exclusively
  * and updates @p pos to point at the found delimiter or at the end of the
  * buffer if neither character occurred.
  * @param buf buffer where to look for
  * @param pos zero-indexed position within buffer
  * @param c1 character to find or '\0' to ignore
  */
 static inline QString extract(const QByteArray &buf, int &pos,
                               const char c1 = '\0')
 {
     int oldpos = pos;
     pos = find(buf, oldpos, c1);
-    return buf.mid(oldpos, pos - oldpos);
+    return QString::fromLatin1(buf.mid(oldpos, pos - oldpos));
 }
 
 /** ignores all whitespaces
  * @param buf buffer to operate on
  * @param pos position to shift to first non-whitespace character
  *  Upon return @p pos will either point to the first non-whitespace
  *  character or to the end of the buffer.
  */
-static inline void ignoreWS(const QString &buf, int &pos)
+static inline void ignoreWS(const QByteArray &buf, int &pos)
 {
     int size = buf.length();
-    while (pos < size && buf[pos].isSpace()) {
+    while (pos < size && (buf[pos] == ' ' || buf[pos] == '\t')) {
         ++pos;
     }
 }
 
 /** parses a quoted string as per rfc 822.
  *
  * If trailing quote is missing, the whole rest of the buffer is returned.
  * @param buf buffer to operate on
  * @param pos position pointing to the leading quote
  * @return the extracted string. @p pos will be updated to point to the
  *  character following the trailing quote.
  */
-static QString parseQuotedString(const QString &buf, int &pos)
+static QString parseQuotedString(const QByteArray &buf, int &pos)
 {
     int size = buf.length();
     QString res;
     res.reserve(size);    // can't be larger than buf
     pos++;        // jump over leading quote
     bool escaped = false; // if true means next character is literal
     bool parsing = true;  // true as long as end quote not found
     while (parsing && pos < size) {
-        const QChar ch = buf[pos++];
+        const QChar ch = QLatin1Char(buf[pos++]);
         if (escaped) {
             res += ch;
             escaped = false;
         } else {
             switch (ch.unicode()) {
             case '"': parsing = false; break;
             case '\\': escaped = true; break;
             default: res += ch; break;
             }/*end switch*/
         }/*end if*/
     }/*wend*/
     res.squeeze();
     return res;
 }
 
 /** parses the header of a data url
  * @param url the data url
  * @param mimeOnly if the only interesting information is the mime type
  * @return DataHeader structure with the header information
  */
 static DataHeader parseDataHeader(const QUrl &url, const bool mimeOnly)
 {
     DataHeader header_info;
 
     // initialize header info members
     header_info.mime_type = QStringLiteral("text/plain");
     header_info.attributes.insert(QStringLiteral("charset"), QStringLiteral("us-ascii"));
     header_info.is_base64 = false;
 
     // decode url and save it
     const QByteArray &raw_url = header_info.url = QByteArray::fromPercentEncoding(url.path(QUrl::FullyEncoded).toLatin1());
     const int raw_url_len = raw_url.length();
 
     header_info.data_offset = 0;
 
     // read mime type
     if (raw_url_len == 0) {
         return header_info;
     }
     const QString mime_type = extract(raw_url, header_info.data_offset).trimmed();
     if (!mime_type.isEmpty()) {
         header_info.mime_type = mime_type;
     }
     if (mimeOnly) {
         return header_info;
     }
 
     if (header_info.data_offset >= raw_url_len) {
         return header_info;
     }
     // jump over delimiter token and return if data reached
-    if (raw_url[header_info.data_offset++] == QLatin1Char(',')) {
+    if (raw_url[header_info.data_offset++] == ',') {
         return header_info;
     }
 
     // read all attributes and store them
     bool data_begin_reached = false;
     while (!data_begin_reached && header_info.data_offset < raw_url_len) {
         // read attribute
         const QString attribute = extract(raw_url, header_info.data_offset, '=').trimmed();
         if (header_info.data_offset >= raw_url_len
-                || raw_url[header_info.data_offset] != QLatin1Char('=')) {
+                || raw_url[header_info.data_offset] != '=') {
             // no assignment, must be base64 option
             if (attribute == QLatin1String("base64")) {
                 header_info.is_base64 = true;
             }
         } else {
             header_info.data_offset++; // jump over '=' token
 
             // read value
             ignoreWS(raw_url, header_info.data_offset);
             if (header_info.data_offset >= raw_url_len) {
                 return header_info;
             }
 
             QString value;
-            if (raw_url[header_info.data_offset] == QLatin1Char('"')) {
+            if (raw_url[header_info.data_offset] == '"') {
                 value = parseQuotedString(raw_url, header_info.data_offset);
                 ignoreWS(raw_url, header_info.data_offset);
             } else {
                 value = extract(raw_url, header_info.data_offset).trimmed();
             }
 
             // add attribute to map
             header_info.attributes[attribute.toLower()] = value;
 
         }/*end if*/
         if (header_info.data_offset < raw_url_len
-                && raw_url[header_info.data_offset] == QLatin1Char(',')) {
+                && raw_url[header_info.data_offset] == ',') {
             data_begin_reached = true;
         }
         header_info.data_offset++; // jump over separator token
     }/*wend*/
 
     return header_info;
 }
 
 #ifdef DATAKIOSLAVE
 DataProtocol::DataProtocol(const QByteArray &pool_socket, const QByteArray &app_socket)
     : SlaveBase("kio_data", pool_socket, app_socket)
 {
 #else
 DataProtocol::DataProtocol()
 {
 #endif
     //qDebug();
 }
 
 /* --------------------------------------------------------------------- */
 
 DataProtocol::~DataProtocol()
 {
     //qDebug();
 }
 
 /* --------------------------------------------------------------------- */
 
 void DataProtocol::get(const QUrl &url)
 {
     ref();
     //qDebug() << this;
 
     const DataHeader hdr = parseDataHeader(url, false);
 
     const int size = hdr.url.length();
     const int data_ofs = qMin(hdr.data_offset, size);
     // FIXME: string is copied, would be nice if we could have a reference only
     const QByteArray url_data = hdr.url.mid(data_ofs);
     QByteArray outData;
 
     if (hdr.is_base64) {
         // base64 stuff is expected to contain the correct charset, so we just
         // decode it and pass it to the receiver
         outData = QByteArray::fromBase64(url_data);
     } else {
         QTextCodec *codec = QTextCodec::codecForName(hdr.attributes[QStringLiteral("charset")].toLatin1());
         if (codec != nullptr) {
             outData = codec->toUnicode(url_data).toUtf8();
         } else {
             outData = url_data;
         }/*end if*/
     }/*end if*/
 
     //qDebug() << "emit mimeType@"<<this;
     emit mimeType(hdr.mime_type);
     //qDebug() << "emit totalSize@"<<this;
     emit totalSize(outData.size());
 
     //qDebug() << "emit setMetaData@"<<this;
 #if defined(DATAKIOSLAVE)
     MetaData::ConstIterator it;
     for (it = hdr.attributes.constBegin(); it != hdr.attributes.constEnd(); ++it) {
         setMetaData(it.key(), it.value());
     }/*next it*/
 #else
     setAllMetaData(hdr.attributes);
 #endif
 
     //qDebug() << "emit sendMetaData@"<<this;
     sendMetaData();
 //qDebug() << "(1) queue size " << dispatchQueue.size();
     // empiric studies have shown that this shouldn't be queued & dispatched
     emit data(outData);
 //qDebug() << "(2) queue size " << dispatchQueue.size();
     DISPATCH(data(QByteArray()));
 //qDebug() << "(3) queue size " << dispatchQueue.size();
     DISPATCH(finished());
 //qDebug() << "(4) queue size " << dispatchQueue.size();
     deref();
 }
 
 /* --------------------------------------------------------------------- */
 
 void DataProtocol::mimetype(const QUrl &url)
 {
     ref();
     emit mimeType(parseDataHeader(url, true).mime_type);
     emit finished();
     deref();
 }
 
 /* --------------------------------------------------------------------- */