A file with name of 1234.56.78.0001.00 Something blah blah.dxf will not export to bitmap correctly. The save dialog will suggest filename of 1234.56.78.0001.jpg instead, truncating everything after last dot.

This bug existed in older versions too because of incorrect handling of file names. As a result, at some point File.getSaveFileName incorrectly truncates the extension (which is empty at the time) and replaces it with jpg. Appending a null extension fixes this, though obviously it's not a correct fix.

Here is a temporary workaround in File.js:

File.getInitialSaveAsPath = function(filePath, extension) {
    var ret = "";

    var fi;

    if (isNull(filePath) || filePath.length === 0) {
        var mdiChild = EAction.getMdiChild();
        var fn;
        if (!isNull(mdiChild)) {
            fn = stripDirtyFlag(EAction.getMdiChild().windowTitle)
        }
        else {
            fn = "File";
        }

        fi = new QFileInfo(QDir.homePath());
        ret = fi.absoluteFilePath() + QDir.separator + fn + "." + extension + ".nothing"; // Workaround here
    } else {
        fi = new QFileInfo(filePath);
        ret = fi.path() + QDir.separator + fi.completeBaseName() + "." + extension + ".nothing"; // Workaround here
    }
    return ret;
};