The schedule shortcode is echoeing an extra "1"

[imath]

Although the favourite schedule email feature is disabled by default as email_fav_sessions_disabled() should prevent the favorite form to be displayed, the form is actually displayed and an extra "1" comes with it. See our ​WordCamp's schedule (above "Les Ateliers")

PS: i've used a css rule to hide the form and the stars

After looking at the code we think the problem is at line 755 of /wc-post-types/wc-post-types.php.

Instead of ob_end_flush() We suggest to use :

$email_form = ob_get_contents();
ob_end_clean();

[coreymckrill]

Just noting that the email feature has actually been enabled at this point in r6349

[coreymckrill]

In 6379:

WordCamp Schedule: Use correct output buffer function for email schedule form

The ob_end_flush function actually returns a boolean instead of the contents
of the buffer. ob_get_clean combines the functionality of ob_get_contents
and ob_end_clean, and so correctly returns the contents of the buffer.

Props imath, coreymckrill
Fixes #3375