Switch things.

app/Http/Controllers/Transaction/LinkController.php

@@ -30,6 +30,7 @@ use FireflyIII\Repositories\Journal\JournalRepositoryInterface;
 use FireflyIII\Repositories\LinkType\LinkTypeRepositoryInterface;
 use Illuminate\Contracts\View\Factory;
 use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
 use Illuminate\Routing\Redirector;
 use Illuminate\View\View;
 use Log;
@@ -157,9 +158,10 @@ class LinkController extends Controller
      *
      * @return RedirectResponse|Redirector
      */
-    public function switchLink(TransactionJournalLink $link)
+    public function switchLink(Request $request)
     {
-        $this->repository->switchLink($link);
+        $linkId = (int)$request->get('id');
+        $this->repository->switchLinkById($linkId);
 
         return redirect(app('steam')->getSafePreviousUrl());
     }

app/Repositories/LinkType/LinkTypeRepository.php

@@ -389,4 +389,21 @@ class LinkTypeRepository implements LinkTypeRepositoryInterface
 
         return TransactionJournalLink::whereDestinationId($two->id)->whereSourceId($one->id)->first();
     }
+
+    /**
+     * @inheritDoc
+     */
+    public function switchLinkById(int $linkId): bool
+    {
+        /** @var TransactionJournalLink $link */
+        $link = TransactionJournalLink::find($linkId);
+        if (null !== $link) {
+
+            if ($link->source->user->id === $this->user->id) {
+                $this->switchLink($link);
+            }
+        }
+
+        return true;
+    }
 }

app/Repositories/LinkType/LinkTypeRepositoryInterface.php

@@ -154,6 +154,13 @@ interface LinkTypeRepositoryInterface
      */
     public function switchLink(TransactionJournalLink $link): bool;
 
+    /**
+     * @param int $linkId
+     *
+     * @return bool
+     */
+    public function switchLinkById(int $linkId): bool;
+
     /**
      * @param LinkType $linkType
      * @param array    $data