Prevent plugin pages access when upgrade pending

If a plugin's code has been upgraded, but the schema is still on the old
version, the plugin is effectively disabled (i.e. its entry points are
not displayed). However, it was still possible to access individual
pages directly, which could lead to errors.

This commit adds an extra check in plugin.php which triggers an error
when the plugin needs to be upgraded.

Fixes #16706

core/constant_inc.php

@@ -378,6 +378,7 @@
 define( 'ERROR_PLUGIN_PAGE_NOT_FOUND', 2502 );
 define( 'ERROR_PLUGIN_UPGRADE_FAILED', 2503 );
 define( 'ERROR_PLUGIN_INSTALL_FAILED', 2504 );
+define( 'ERROR_PLUGIN_UPGRADE_NEEDED', 2505 );
 define( 'ERROR_PLUGIN_GENERIC', 2599 );
 
 # ERROR_COLUMNS_*

lang/strings_english.txt

@@ -1668,6 +1668,7 @@ $MANTIS_ERROR[ERROR_PLUGIN_ALREADY_INSTALLED] = 'Plugin is already installed.';
 $MANTIS_ERROR[ERROR_PLUGIN_PAGE_NOT_FOUND] = 'Plugin page not found.';
 $MANTIS_ERROR[ERROR_PLUGIN_INSTALL_FAILED] = 'Plugin installation failed: %1$s.';
 $MANTIS_ERROR[ERROR_PLUGIN_UPGRADE_FAILED] = 'Upgrading the plugin schema failed in block #%1$s.';
+$MANTIS_ERROR[ERROR_PLUGIN_UPGRADE_NEEDED] = 'The "%1$s" plugin needs to be upgraded before you can access this page.';
 $MANTIS_ERROR[ERROR_PLUGIN_GENERIC] = 'There was an unknown error "%1$s" during execution of the "%2$s" plugin.';
 $MANTIS_ERROR[ERROR_COLUMNS_DUPLICATE] = 'Field "%1$s" contains duplicate column "%2$s".';
 $MANTIS_ERROR[ERROR_COLUMNS_INVALID] = 'Field "%1$s" contains invalid field "%2$s".';

plugin.php

@@ -57,6 +57,11 @@
 		trigger_error( ERROR_PLUGIN_PAGE_NOT_FOUND, ERROR );
 }
 
+if( plugin_needs_upgrade( $g_plugin_cache[$t_basename] ) ) {
+	error_parameters( $t_basename );
+	trigger_error( ERROR_PLUGIN_UPGRADE_NEEDED, ERROR );
+}
+
 plugin_push_current( $t_basename );
 include( $t_page );