title: Encoding::UndefinedConversionError
body: <p>I keep getting an <code>Encoding::UndefinedConversionError - &quot;\xC2&quot; from ASCII-8BIT to UTF-8</code> every time I try to convert a hash into a JSON string. I tried with <code>[.encode | .force_encoding]([&quot;UTF-8&quot; | &quot;ASCII-8BIT&quot; ])</code>, chaining <code>.encode</code> with <code>.force_encoding</code>, backwards, switching parameters but nothing seemed to work so I caught the error like this:</p>
  <pre><code>begin
    menu.to_json
  rescue Encoding::UndefinedConversionError
    puts $!.error_char.dump
    p $!.error_char.encoding
  end
  </code></pre>
  <p>Where menu is a sequel's dataset.to_hash with content from a MySQL DB, utf8_general_ci encoding and returned this:</p>
  <blockquote>
  <p>&quot;\xC2&quot;</p>
  <p>&lt;#Encoding:ASCII-8BIT&gt;</p>
  </blockquote>
  <p>The encoding never changes, no matter what <code>.encode</code>/<code>.force_encoding</code> I use. I've even tried to replace the string <code>.gsub!(/\\\xC2/)</code> without luck.</p>
  <p>Any ideas?</p>