5 files changed, 53 insertions, 5 deletions
diff --git a/phpBB/includes/acp/acp_board.php b/phpBB/includes/acp/acp_board.php
index c2a004c395..f89f5535eb 100644
--- a/phpBB/includes/acp/acp_board.php
+++ b/phpBB/includes/acp/acp_board.php
@@ -356,6 +356,7 @@ class acp_board
 						'load_user_activity_limit'		=> array('lang' => 'LOAD_USER_ACTIVITY_LIMIT',		'validate' => 'int:0:99999999',	'type' => 'number:0:99999999', 'explain' => true),
 						'load_tplcompile'		=> array('lang' => 'RECOMPILE_STYLES',		'validate' => 'bool',	'type' => 'radio:yes_no', 'explain' => true),
 						'allow_cdn'				=> array('lang' => 'ALLOW_CDN',				'validate' => 'bool',	'type' => 'radio:yes_no', 'explain' => true),
+						'enable_accurate_pm_button'	=> array('lang' => 'YES_ACCURATE_PM_BUTTON',	'validate' => 'bool',	'type' => 'radio:yes_no', 'explain' => true),
 						'allow_live_searches'	=> array('lang' => 'ALLOW_LIVE_SEARCHES',	'validate' => 'bool',	'type' => 'radio:yes_no', 'explain' => true),
 
 						'legend3'				=> 'CUSTOM_PROFILE_FIELDS',
diff --git a/phpBB/install/schemas/schema_data.sql b/phpBB/install/schemas/schema_data.sql
index 1f92439c70..4dfe5e94aa 100644
--- a/phpBB/install/schemas/schema_data.sql
+++ b/phpBB/install/schemas/schema_data.sql
@@ -106,6 +106,7 @@ INSERT INTO phpbb_config (config_name, config_value) VALUES ('email_enable', '1'
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('email_force_sender', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('email_max_chunk_size', '50');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('email_package_size', '20');
+INSERT INTO phpbb_config (config_name, config_value) VALUES ('enable_accurate_pm_button', '1');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('enable_confirm', '1');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('enable_mod_rewrite', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('allow_board_notifications', '1');
diff --git a/phpBB/language/en/acp/board.php b/phpBB/language/en/acp/board.php
index 25d70813f6..0b2e6372a6 100644
--- a/phpBB/language/en/acp/board.php
+++ b/phpBB/language/en/acp/board.php
@@ -406,6 +406,8 @@ $lang = array_merge($lang, array(
 	'RECOMPILE_STYLES_EXPLAIN'		=> 'Check for updated style components on filesystem and recompile.',
 	'YES_ANON_READ_MARKING'			=> 'Enable topic marking for guests',
 	'YES_ANON_READ_MARKING_EXPLAIN'	=> 'Stores read/unread status information for guests. If disabled, posts are always marked read for guests.',
+	'YES_ACCURATE_PM_BUTTON'			=> 'Enable accurate PM indicator in topic pages',
+	'YES_ACCURATE_PM_BUTTON_EXPLAIN'	=> 'If this setting is enabled, only users who are permitted to read private messages will have a private message button.',
 	'YES_BIRTHDAYS'					=> 'Enable birthday listing',
 	'YES_BIRTHDAYS_EXPLAIN'			=> 'If disabled the birthday listing is no longer displayed. To let this setting take effect the birthday feature needs to be enabled too.',
 	'YES_JUMPBOX'					=> 'Enable display of jumpbox',
diff --git a/phpBB/phpbb/db/migration/data/v32x/enable_accurate_pm_button.php b/phpBB/phpbb/db/migration/data/v32x/enable_accurate_pm_button.php
new file mode 100644
index 0000000000..a7b99606f7
--- /dev/null
+++ b/phpBB/phpbb/db/migration/data/v32x/enable_accurate_pm_button.php
@@ -0,0 +1,36 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\db\migration\data\v32x;
+
+class enable_accurate_pm_button extends \phpbb\db\migration\migration
+{
+	static public function depends_on()
+	{
+		return array(
+			'\phpbb\db\migration\data\v32x\v322',
+		);
+	}
+
+	public function effectively_installed()
+	{
+		return isset($this->config['enable_accurate_pm_button']);
+	}
+
+	public function update_data()
+	{
+		return array(
+			array('config.add', array('enable_accurate_pm_button', '1')),
+		);
+	}
+}
diff --git a/phpBB/viewtopic.php b/phpBB/viewtopic.php
index 38eba32374..9e6e4538d6 100644
--- a/phpBB/viewtopic.php
+++ b/phpBB/viewtopic.php
@@ -1576,12 +1576,20 @@ if (count($attach_list))
 	}
 }
 
-// Get the list of users who can receive private messages
-$can_receive_pm_list = $auth->acl_get_list(array_keys($user_cache), 'u_readpm');
-$can_receive_pm_list = (empty($can_receive_pm_list) || !isset($can_receive_pm_list[0]['u_readpm'])) ? array() : $can_receive_pm_list[0]['u_readpm'];
+if ($config['enable_accurate_pm_button'])
+{
+	// Get the list of users who can receive private messages
+	$can_receive_pm_list = $auth->acl_get_list(array_keys($user_cache), 'u_readpm');
+	$can_receive_pm_list = (empty($can_receive_pm_list) || !isset($can_receive_pm_list[0]['u_readpm'])) ? array() : $can_receive_pm_list[0]['u_readpm'];
 
-// Get the list of permanently banned users
-$permanently_banned_users = phpbb_get_banned_user_ids(array_keys($user_cache), false);
+	// Get the list of permanently banned users
+	$permanently_banned_users = phpbb_get_banned_user_ids(array_keys($user_cache), false);
+}
+else
+{
+	$can_receive_pm_list = array_keys($user_cache);
+	$permanently_banned_users = [];
+}
 
 $i_total = count($rowset) - 1;
 $prev_post_id = '';