title: Flask resets the connection instead of returning a 413, when the file is to big
body: <p>When <code>MAX_CONTENT_LENGTH</code>is definded, Flask should return an 413, but in my case it resets the connection with this error: <code>Error 101 (net::ERR_CONNECTION_RESET): The connection was reset.</code></p>
  
  <p>I attached a example built upon the file upload pattern from Flask.</p>
  
  <p>I use Chrome 15.0.874.5.</p>
  
  <pre><code>import os
  from flask import Flask, request, redirect, url_for, send_from_directory
  from werkzeug import secure_filename
  
  UPLOAD_FOLDER = 'uploads/'
  ALLOWED_EXTENSIONS = set(['txt', 'pdf', 'png', 'jpg', 'jpeg', 'gif','bib','mp3'])
  
  app = Flask(__name__)
  app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
  def allowed_file(filename):
      return '.' in filename and \
             filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS
  
  @app.route('/', methods=['GET', 'POST'])
  def upload_file():
      if request.method == 'POST':
          file = request.files['file']
          if file and allowed_file(file.filename):
              filename = secure_filename(file.filename)
              file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
              return redirect(url_for('uploaded_file',
                                      filename=filename))
      return '''
      &lt;!doctype html&gt;
      &lt;title&gt;Upload new File&lt;/title&gt;
      &lt;h1&gt;Upload new File&lt;/h1&gt;
      &lt;form action="" method=post enctype=multipart/form-data&gt;
        &lt;p&gt;&lt;input type=file name=file&gt;
           &lt;input type=submit value=Upload&gt;
      &lt;/form&gt;
      '''
  
  @app.route('/uploads/&lt;filename&gt;')
  def uploaded_file(filename):
      return send_from_directory(app.config['UPLOAD_FOLDER'],
                                 filename)
  
  @app.errorhandler(413)
  def file_to_big(e):
      return 'File to big'
  
  if __name__ == '__main__':
      app.config['MAX_CONTENT_LENGTH'] = 1024 * 1024
      app.run(debug=True)                    
  </code></pre>