mvc: merge API fixes as suggested by @adschellevis

src/opnsense/mvc/app/controllers/OPNsense/Base/ApiControllerBase.php

@@ -137,11 +137,12 @@ class ApiControllerBase extends ControllerRoot
                                     $req_c = $object_info->getMethod($callMethodName)->getNumberOfRequiredParameters();
                                     if ($req_c > count($dispatcher->getParams())) {
                                         $dispatchError = 'action ' . $dispatcher->getActionName() .
-                                            ' expects at least '. $req_c . ' parameter(s)';
-                                    } else {
-                                        // if body is send as json data, parse to $_POST first
-                                        $dispatchError = $this->parseJsonBodyData();
+                                            ' expects at least ' . $req_c . ' parameter(s)';
+                                    }
                                 }
+                                // if body is send as json data, parse to $_POST first
+                                $dispatchError = empty($dispatchError) ? $this->parseJsonBodyData() : $dispatchError;
+
                                 if ($dispatchError != null) {
                                     // send error to client
                                     $this->response->setStatusCode(400, "Bad Request");
@@ -153,7 +154,6 @@ class ApiControllerBase extends ControllerRoot
                                     $this->response->send();
                                     return false;
                                 }
-                                }
 
                                 return true;
                             }
@@ -192,6 +192,8 @@ class ApiControllerBase extends ControllerRoot
                 $this->response->setStatusCode(403, "Forbidden");
                 return false;
             }
+            // when request is using a json body (based on content type), parse it first
+            $this->parseJsonBodyData();
         }
     }