mvc: handle execution error more gracefully; closes #1413

src/opnsense/mvc/app/controllers/OPNsense/Core/Api/FirmwareController.php

@@ -446,6 +446,7 @@ class FirmwareController extends ApiControllerBase
 
         return $result;
     }
+
     /**
      * retrieve upgrade status (and log file of current process)
      */
@@ -457,7 +458,7 @@ class FirmwareController extends ApiControllerBase
 
         $result['log'] = $cmd_result;
 
-        if (trim($cmd_result) == 'Execute error') {
+        if ($cmd_result == null) {
             $result['status'] = 'error';
         } elseif (strpos($cmd_result, '***DONE***') !== false) {
             $result['status'] = 'done';

src/opnsense/mvc/app/controllers/OPNsense/Diagnostics/Api/SystemhealthController.php

@@ -540,7 +540,9 @@ class SystemhealthController extends ApiControllerBase
         if ($rrd_details['filename'] != "") {
             $backend = new Backend();
             $response = $backend->configdpRun("systemhealth fetch ", array($rrd_details['filename']));
-            $xml = @simplexml_load_string($response);
+            if ($response != null) {
+                $xml = @simplexml_load_string($response);
+            }
         }
 
         if ($xml !== false) {

src/opnsense/mvc/app/library/OPNsense/Core/Backend.php

@@ -77,6 +77,7 @@ class Backend
     public function configdRun($event, $detach = false, $timeout = 120, $connect_timeout = 10)
     {
         $endOfStream = chr(0).chr(0).chr(0);
+        $errorOfStream = 'Execute error';
         $poll_timeout = 2; // poll timeout interval
 
         // wait until socket exist for a maximum of $connect_timeout
@@ -122,7 +123,12 @@ class Backend
             }
         }
 
-        return  str_replace($endOfStream, "", $resp);
+        if (strlen($resp) >= strlen($errorOfStream) &&
+            substr($resp, 0, strlen($errorOfStream)) == $errorOfStream) {
+            return null;
+        }
+
+        return str_replace($endOfStream, '', $resp);
     }
 
     /**