Teaser displays with entire content as well

After further digging, it appears to be a bug in bookreview_view method. In the 4.7 version of the code, there's an if($page) that was ignored in the upgrade to 5.x. The following code behaves as expected:

function bookreview_view(&$node, $teaser = FALSE, $page = FALSE) {
   global $theme;

   $node = node_prepare($node, $teaser);
   if($page) {
     $themefunction = "{$theme}_bookreview_content";
     if (!function_exists($themefunction)) {
       $themefunction = 'bookreview_content';
     }
    // $node = node_prepare($node, $teaser);

     $node->content['bookreview'] = array(
       '#value' => theme($themefunction, $node),
       '#weight' => 1,
     );
   }

   return $node;
}

I attempted to create a patch, but line endings had changed and produced an overly verbose patch.