From e6e9b7fc9c8391cffca9c7c006bd3336a48a03cf Mon Sep 17 00:00:00 2001
From: Happy-melon <happy-melon@users.mediawiki.org>
Date: Fri, 18 Mar 2011 13:03:26 +0000
Subject: [PATCH] (bug 27403) saved user preferences which are subsequently
 disabled with $wgHiddenPrefs are not used in output, but are retained in the
 database in case the preference is subsequently re-enabled.

---
 includes/Preferences.php | 10 ++++++++++
 includes/User.php        | 30 ++++++++++++++++++++++++++++--
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/includes/Preferences.php b/includes/Preferences.php
index 57dab312b5..37563ddfdf 100644
--- a/includes/Preferences.php
+++ b/includes/Preferences.php
@@ -1315,6 +1315,16 @@ class Preferences {
 			unset( $formData[$b] );
 		}
 
+		# If users have saved a value for a preference which has subsequently been disabled
+		# via $wgHiddenPrefs, we don't want to destroy that setting in case the preference
+		# is subsequently re-enabled
+		# TODO: maintenance script to actually delete these
+		foreach( $wgHiddenPrefs as $pref ){
+			# If the user has not set a non-default value here, the default will be returned
+			# and subsequently discarded
+			$formData[$pref] = $wgUser->getOption( $pref, null, true );
+		}
+
 		//  Keeps old preferences from interfering due to back-compat
 		//  code, etc.
 		$wgUser->resetOptions();
diff --git a/includes/User.php b/includes/User.php
index 94fb46262b..8be2b3c42c 100644
--- a/includes/User.php
+++ b/includes/User.php
@@ -1963,11 +1963,13 @@ class User {
 	 *
 	 * @param $oname String The option to check
 	 * @param $defaultOverride String A default value returned if the option does not exist
+	 * @bool $ignoreHidden = whether to ignore the effects of $wgHiddenPrefs
 	 * @return String User's current value for the option
 	 * @see getBoolOption()
 	 * @see getIntOption()
 	 */
-	function getOption( $oname, $defaultOverride = null ) {
+	function getOption( $oname, $defaultOverride = null, $ignoreHidden = false ) {
+		global $wgHiddenPrefs;
 		$this->loadOptions();
 
 		if ( is_null( $this->mOptions ) ) {
@@ -1977,6 +1979,15 @@ class User {
 			$this->mOptions = User::getDefaultOptions();
 		}
 
+		# We want 'disabled' preferences to always behave as the default value for
+		# users, even if they have set the option explicitly in their settings (ie they
+		# set it, and then it was disabled removing their ability to change it).  But
+		# we don't want to erase the preferences in the database in case the preference
+		# is re-enabled again.  So don't touch $mOptions, just override the returned value
+		if( in_array( $oname, $wgHiddenPrefs ) && !$ignoreHidden ){
+			return self::getDefaultOption( $oname );
+		}
+
 		if ( array_key_exists( $oname, $this->mOptions ) ) {
 			return $this->mOptions[$oname];
 		} else {
@@ -1990,8 +2001,23 @@ class User {
 	 * @return array
 	 */
 	public function getOptions() {
+		global $wgHiddenPrefs;
 		$this->loadOptions();
-		return $this->mOptions;
+		$options = $this->mOptions;
+
+		# We want 'disabled' preferences to always behave as the default value for
+		# users, even if they have set the option explicitly in their settings (ie they
+		# set it, and then it was disabled removing their ability to change it).  But
+		# we don't want to erase the preferences in the database in case the preference
+		# is re-enabled again.  So don't touch $mOptions, just override the returned value
+		foreach( $wgHiddenPrefs as $pref ){
+			$default = self::getDefaultOption( $pref );
+			if( $default !== null ){
+				$options[$pref] = $default;
+			}
+		}
+
+		return $options;
 	}
 
 	/**
-- 
2.20.1