Avoid undefined class variables

boot.php

@@ -510,6 +510,11 @@ function startup() {
  */
 function get_app() {
 	global $a;
+
+	if (empty($a)) {
+		$a = new App(dirname(__DIR__));
+	}
+
 	return $a;
 }
 

include/auth_ejabberd.php

@@ -49,7 +49,7 @@ require_once("boot.php");
 
 global $a;
 
-if (is_null($a)) {
+if (empty($a)) {
 	$a = new App(dirname(__DIR__));
 }
 

include/cli_startup.php

@@ -10,7 +10,7 @@ require_once('boot.php');
 function cli_startup() {
 	global $a;
 
-	if (is_null($a)) {
+	if (empty($a)) {
 		$a = new App(dirname(__DIR__));
 	}
 

include/dbstructure.php

@@ -1760,7 +1760,7 @@ function db_definition() {
 function dbstructure_run(&$argv, &$argc) {
 	global $a;
 
-	if (is_null($a)) {
+	if (empty($a)) {
 		$a = new App(dirname(__DIR__));
 	}
 

include/poller.php

@@ -23,7 +23,9 @@ function poller_run($argv, $argc){
 
 	$poller_up_start = microtime(true);
 
+	if (empty($a)) {
 		$a = new App(dirname(__DIR__));
+	}
 
 	require_once ".htconfig.php";
 	require_once "include/dba.php";

include/shadowupdate.php

@@ -9,7 +9,7 @@ require_once("include/threads.php");
 function shadowupdate_run(&$argv, &$argc){
 	global $a;
 
-	if (is_null($a)) {
+	if (empty($a)) {
 		$a = new App(dirname(__DIR__));
 	}
 

index.php

@@ -20,7 +20,9 @@ use Friendica\Core\Config;
 require_once 'boot.php';
 require_once 'object/BaseObject.php';
 
+if (empty($a)) {
 	$a = new App(__DIR__);
+}
 BaseObject::set_app($a);
 
 // We assume that the index.php is called by a frontend process

util/db_update.php

@@ -11,7 +11,9 @@ use Friendica\App;
  */
 require_once("boot.php");
 
+if (empty($a)) {
 	$a = new App(dirname(__DIR__));
+}
 @include(".htconfig.php");
 
 $lang = get_browser_language();

util/maintenance.php

@@ -5,7 +5,10 @@ use Friendica\Core\Config;
 
 require_once("boot.php");
 
+if (empty($a)) {
 	$a = new App(dirname(__DIR__));
+}
+
 @include(".htconfig.php");
 
 $lang = get_browser_language();

util/typo.php

@@ -13,7 +13,9 @@ ini_set('log_errors', '0');
 
 include 'boot.php';
 
+if (empty($a)) {
 	$a = new App(dirname(__DIR__));
+}
 
 if (x($a->config, 'php_path')) {
 	$phpath = $a->config['php_path'];