Fix Wordpress co-authors-plus plugin taxonomy when upgrading from 2.0 to 3.0

co-authors-plus_update_taxonomy.diff

commit 36419d0a0d0d6d7328877a3d9153b1aa4c76aa11
Author: Jeffrey Clark <jaclark@fnal.gov>
Date:   Thu Dec 6 13:55:42 2012 -0600

    fix co-authors-plus taxonomy bug when slug is not unique
    http://core.trac.wordpress.org/ticket/5809
    http://wordpress.org/support/topic/authors-names-dont-show-up-in-various-places-taxonomy-30

diff --git a/wp-content/plugins/co-authors-plus/co-authors-plus.php b/wp-content/plugins/co-authors-plus/co-authors-plus.php
index ec25fd0..9d8d6d9 100644
--- a/wp-content/plugins/co-authors-plus/co-authors-plus.php
+++ b/wp-content/plugins/co-authors-plus/co-authors-plus.php
@@ -56,6 +56,8 @@ class coauthors_plus {
 
        var $having_terms = '';
 
+       var $_options = false;
+
        /**
         * __construct()
         */
@@ -188,6 +190,42 @@ class coauthors_plus {
                // Apply some targeted filters
                add_action( 'load-edit.php', array( $this, 'load_edit' ) );
 
+               // Upgrade?
+               $last_upgrade = $this->get_option( 'upgrade' );
+               if ( $last_upgrade < COAUTHORS_PLUS_VERSION ) {
+                       require_once( dirname(__FILE__) . DIRECTORY_SEPARATOR . 'upgrade.php' );
+                       coauthors_plus_upgrade( $last_upgrade );
+                       $this->set_option( 'upgrade', COAUTHORS_PLUS_VERSION );
+               }
+       }
+
+       /**
+        * Retrieve plugin global options
+        *
+        * @since 3.0.3
+        */
+       function get_option( $key = null ) {
+               if ( ! $this->_options ) {
+                       $this->_options = get_option( get_class( $this ) );
+               }
+               if ( isset( $key ) ) {
+                       return isset( $this->_options[$key] ) ? $this->_options[$key] : null;
+               }
+               return $this->_options;
+       }
+
+       /**
+        * Set plugin global options
+        *
+        * @since 3.0.3
+        */
+       function set_option( $key, $value = null ) {
+               if ( is_array($key) ) {
+                       $this->_options = array_merge($this->_options, $key);
+               } else {
+                       $this->_options[$key] = $value;
+               }
+               update_option( get_class($this), $this->_options );
        }
 
        /**
diff --git a/wp-content/plugins/co-authors-plus/upgrade.php b/wp-content/plugins/co-authors-plus/upgrade.php
index ca73570..a1a7d45 100644
--- a/wp-content/plugins/co-authors-plus/upgrade.php
+++ b/wp-content/plugins/co-authors-plus/upgrade.php
@@ -3,6 +3,7 @@ function coauthors_plus_upgrade( $from ) {
        // TODO: handle upgrade failures
        
        if( $from < 2.0 ) coauthors_plus_upgrade_20();
+       if( $from < 3.0 ) coauthors_plus_upgrade_30();
 }
 
 /** 
@@ -43,4 +44,27 @@ function coauthors_plus_upgrade_20 () {
                        
                }
        }
+       $coauthors_plus->set_option( 'upgrade', '2.0' );
+}
+
+/**
+ * Upgrade to 3.0
+ * Add 'cap-' prefix to author taxonomy terms to work-around Wordpress core limitation.
+ * See: http://core.trac.wordpress.org/ticket/5809
+ */
+function coauthors_plus_upgrade_30 () {
+       global $coauthors_plus;
+       global $wpdb;
+
+       $loop_query = "SELECT term_id, name, slug FROM {$wpdb->prefix}terms WHERE term_id IN (SELECT term_id FROM {$wpdb->prefix}term_taxonomy WHERE taxonomy = '{$coauthors_plus->coauthor_taxonomy}')";
+       foreach( $wpdb->get_results($loop_query) as $term ) {
+               if ( substr( $term->slug, 0, 4 ) !== 'cap-' ) {
+                       $wpdb->query(
+                               $wpdb->prepare(
+                                       "UPDATE {$wpdb->prefix}terms SET slug = %s WHERE term_id = %d", 'cap-' . sanitize_title( $term->name ), $term->term_id
+                               )
+                       );
+               }
+       }
+       $coauthors_plus->set_option( 'upgrade', '3.0' );
 }