Update to wordpress

I’m trying to figure this out, too.

I’ve changed that line from:
$version['spec'] = $subver[1];
to
$version['spec'] = isset($subver[1]) ? $subver[1] : NULL;

Still testing, not guaranteed to work.

My process:
Here is the function in admin.class.php that includes line 129:

public function getWpVersion() {
      global $wp_version;
      $version = array();

      $ver = explode('.', $wp_version);
      $version['major'] = $ver[0];
      $vc = count($ver);
      if($vc == 2) {
        $subver = explode('-', $ver[1]);
        $version['minor'] = $subver[0];
        $version['spec'] = $subver[1];
        $version['str'] = $version['major'].'.'.$version['minor'].((!empty($version['spec'])) ? ' ('.$version['spec'].')' : '');
      }
      else {
        $version['minor'] = $ver[1];
        $version['build'] = $ver[2];
        $version['str'] = $wp_version;
      } 

      return $version;
    }

What I notice is that $wp_version is “3.5” in the latest WP.
$ver is an array of the version parts (as separated by ‘.’), e.g. array(3, 5).

$vc therefor equals 2.

$subver is trying to create an array of the “5” part of “3.5”, splitting at “-” which doesn’t exist, so we have $subver = array(5) and $subver[1] doesn’t exist (illegal offset).

I’m not sure where this is being called, but it’s safe to assume that $version (the returned variable) needs to be an array, so we can’t just assign $version the value of $wp_version.

We can do a shorthand conditional statement instead, assigning $version[‘spec’] the value NULL if $subver[1] is not set.