From 9e63702387a0e6943f2ea53558e8ae50a51f1f94 Mon Sep 17 00:00:00 2001
From: Josef Citrine <josefcitrine@googlemail.com>
Date: Sat, 10 Dec 2016 16:39:58 +0000
Subject: [PATCH 1/2] Fixed genre deletion

---
 app/Jobs/DeleteGenre.php | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/app/Jobs/DeleteGenre.php b/app/Jobs/DeleteGenre.php
index 30a33a71..6aed5171 100644
--- a/app/Jobs/DeleteGenre.php
+++ b/app/Jobs/DeleteGenre.php
@@ -47,10 +47,6 @@ class DeleteGenre extends Job implements ShouldQueue
         $this->executingUser = Auth::user();
         $this->genreToDelete = $genreToDelete;
         $this->destinationGenre = $destinationGenre;
-
-        // The genre is deleted synchronously before the job is executed in
-        // order to prevent race conditions.
-        $this->genreToDelete->delete();
     }
 
     /**
@@ -67,14 +63,14 @@ class DeleteGenre extends Job implements ShouldQueue
 
         // This is done instead of a single UPDATE query in order to
         // generate revision logs for the change.
-        $this->genreToDelete->tracks()->chunk(200, function ($tracks) {
-            foreach ($tracks as $track) {
-                /** @var Track $track */
+        $this->genreToDelete->tracks()->each(function ($track) {
+            /** @var Track $track */
 
-                $track->genre_id = $this->destinationGenre->id;
-                $track->save();
-                $track->updateTags();
-            }
+            $track->genre_id = $this->destinationGenre->id;
+            $track->save();
+            $track->updateTags();
         });
+
+        $this->genreToDelete->delete();
     }
 }

From d7fc5f02cfd4424a1f5144b3e0c6482071275362 Mon Sep 17 00:00:00 2001
From: Josef Citrine <josefcitrine@gmail.com>
Date: Wed, 17 May 2017 02:38:22 +0100
Subject: [PATCH 2/2] Fixed race condition in genre deletion

---
 app/Jobs/DeleteGenre.php | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/app/Jobs/DeleteGenre.php b/app/Jobs/DeleteGenre.php
index 6aed5171..2c5bcd2f 100644
--- a/app/Jobs/DeleteGenre.php
+++ b/app/Jobs/DeleteGenre.php
@@ -63,14 +63,17 @@ class DeleteGenre extends Job implements ShouldQueue
 
         // This is done instead of a single UPDATE query in order to
         // generate revision logs for the change.
-        $this->genreToDelete->tracks()->each(function ($track) {
-            /** @var Track $track */
-
-            $track->genre_id = $this->destinationGenre->id;
-            $track->save();
-            $track->updateTags();
-        });
+        $tracks = Track::whereGenreId($this->genreToDelete->id)->get();
 
         $this->genreToDelete->delete();
+        $chunks = $tracks->chunk(200);
+
+        foreach ($chunks as $chunk) {
+            foreach ($chunk as $track) {
+                $track->genre_id = $this->destinationGenre->id;
+                $track->save();
+                $track->updateTags();
+            }
+        }
     }
 }