BUGFIX: Keep existing arguments in filter mode

E.g. to support paginate widget arguments.

Classes/Controller/SearchController.php

@@ -49,9 +49,12 @@ class SearchController extends ActionController
         if (isset($this->settings['searching']['mode']) && $this->settings['searching']['mode'] === 'filter'
             && $this->request->hasArgument('searchRequest') === false
         ) {
-            $this->request->setArguments([
+            $this->request->setArguments(array_merge(
+                $this->request->getArguments(),
+                [
                     'searchRequest' => $this->objectManager->get(SearchRequest::class),
-            ]);
+                ]
+            ));
         }
     }
 

Tests/Unit/Controller/SearchControllerTest.php

@@ -83,6 +83,35 @@ class SearchControllerTest extends AbstractUnitTestCase
         );
     }
 
+    /**
+     * @test
+     */
+    public function searchRequestArgumentIsAddedToExistingArguments()
+    {
+        $this->request->setArguments([
+            '@widget_0' => [
+                'currentPage' => '7',
+            ]
+        ]);
+        $this->inject($this->subject, 'settings', [
+            'searching' => [
+                'mode' => 'filter',
+            ]
+        ]);
+
+        $this->subject->initializeSearchAction();
+        $this->assertInstanceOf(
+            SearchRequest::class,
+            $this->request->getArgument('searchRequest'),
+            'Search request was not created.'
+        );
+        $this->assertSame(
+            ['currentPage' => '7'],
+            $this->request->getArgument('@widget_0'),
+            'Existing arguments were not kept.'
+        );
+    }
+
     /**
      * @test
      */