Emailed %email_values shows blank for text field when value is submitted as '0'

The problem is in theme_webform_element_text() at this point $value is '0' which evaluates to false.

// Add the value to the output.
  if ($value) {
    $output .= (strpos($value, "\n") === FALSE ? ' ' : "\n") . $value;
2  }

One quickie workaround is to change it before it's rendered. Alternately, I could have recreated most of the code in my theme function. The real fix is to check if $value === 0.

/**
* Work-around to force webform to show ' 0 ' when text value is '0'.
*/
function MYTHEME_webform_element_text($variables) {
  $value = $variables['element']['#children'];
  if (trim($value) === '0') {
    $variables['element']['#children'] = ' 0';
  }
  // Call the default theme function if there is a value.
  return theme_webform_element_text($variables);
}