Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-63434

QXmlStreamWriter places xmlns attribute in the wrong tag if there are no whitespaces

    XMLWordPrintable

Details

    • f286027e6b8fb89e05d64a2a848ec18a95934526 (qt/qtbase/5.12)

    Description

      Scenario: reading an xml file with QXmlStreamReader and writing every (unmodified) token to another file with QXmlStreamWriter.

      while (!reader.atEnd())
      {
          reader.readNext();
          writer.writeCurrentToken(reader);
      }
      

      Input file:

      <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
      <root>
      	<father><child xmlns:unknown='http://mydomain'>Text</child></father>
      </root>
      

      Expected: output should equal input. Actual:

      <?xml version="1.0" encoding="UTF-8"?><root>
      	<father xmlns:unknown="http://mydomain"><child>Text</child></father>
      </root>
      

      Note that the xmlns attribute was moved to the "father" tag. If any whitespace (space, tab, newline) is added after the "father" tag, namespace is correctly placed in the "child" tag. Tags and namespaces seem to be read correctly by the QXmlStreamReader.

      The problem can be reproduced with the XML Stream Lint Example from Qt docs and the attached xml file.

      If confirmed, this is a severe issue for any applications using xml data.

      Also note other small problems:

      1. "standalone" attribute is removed from the start token;
      2. the first newline is arbitrarily removed

      A workaround to 1. is to handle the startDocument token explicitly:

      if( reader.isStartDocument() )
      {
      	writer.setCodec( QTextCodec::codecForName( reader.documentEncoding().toLatin1() ) );
      	writer.writeStartDocument( reader.documentVersion().toString(),
      reader.isStandaloneDocument() );
      } else
      	writer.writeCurrentToken( reader );
      

      Side note: the reader API returns QStringRef while the writer takes const QString, thus requiring an unnecessary copy for every string ref.

       

       

      Attachments

        No reviews matched the request. Check your Options in the drop-down menu of this sections header.

        Activity

          People

            hjk hjk
            narcolessico Eugenio Rustico
            Votes:
            5 Vote for this issue
            Watchers:
            7 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:

              Gerrit Reviews

                There are no open Gerrit changes