js.php returns JSON with text/html content-type header

It seems that there is no attempt to set a content type, just the following code is run to output JSON:

print drupal_to_js($return);

Sending JSON with text/html headers will cause some browsers (such as Chrome) to raise warnings in their error logs that the wrong content type was used for Javascript.

In Drupal 6, there's a utility function available in common.inc to return JSON with the proper headers, drupal_json().

The attached patch swaps out drupal_to_js() with drupal_json() to write the correct headers.

This doesn't affect functions that take care of their own JSON output, or other content type output.