Use wp_safe_redirect instead of wp_redirect
Fix broken link on compare fork screen

On this screen, the $post global is null. I assume the intention is to
link back to the original pos.
Fork_Merge->merge() returns post ID, not post object.

Fork_Merge->merge() returns the value from wp_update_post(), which is
an integer (the post ID), not a post object
Merge branch 'admin_fixes'
Merge branch 'intercept_publish_fix'