From df00f4176501207dc2d736a4b7ea4e1dea262239 Mon Sep 17 00:00:00 2001
From: ema <mccoy39082@163.com>
Date: Fri, 20 Dec 2024 22:48:30 +0800
Subject: [PATCH] Safely disposing GIF-related memory resources

---
 .../AnimatedImage/Providers/GifProvider.cs    | 21 +++++++++----------
 .../MetaProvider.cs                           |  3 +--
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/AnimatedImage/Providers/GifProvider.cs b/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/AnimatedImage/Providers/GifProvider.cs
index 5174fe20..edde70f9 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/AnimatedImage/Providers/GifProvider.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/AnimatedImage/Providers/GifProvider.cs
@@ -19,6 +19,7 @@
 using QuickLook.Common.Helpers;
 using QuickLook.Common.Plugin;
 using System;
+using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.IO;
@@ -43,9 +44,9 @@ internal class GifProvider : AnimationProvider
     private NativeProvider _nativeProvider;
 
     private int[] _frameDelays; // in millisecond
-    private int _frameCount = 0;
+    private readonly int _frameCount = 0;
     private int _frameIndex = 0;
-    private int _maxLoopCount = 0; // 0 - infinite loop
+    private readonly int _maxLoopCount = 0; // 0 - infinite loop
     private int _loopIndex = 0;
 
     private TimeSpan _minTickTimeInMillisecond = TimeSpan.FromMilliseconds(20);
@@ -95,20 +96,18 @@ public override void Dispose()
 
         try
         {
-            if (_bitmap != null)
+            lock (_bitmap ?? new object()) // Lock to prevent null reference exception
             {
-                lock (_bitmap)
-                {
-                    _stream?.Dispose();
-                    _bitmap?.Dispose();
+                _bitmap?.Dispose();
+                _bitmap = null;
 
-                    _bitmap = null;
-                    _stream = null;
-                }
+                _stream?.Dispose();
+                _stream = null;
             }
         }
-        catch
+        catch (Exception e)
         {
+            Debug.WriteLine(e);
         }
 
         _frame = null;
diff --git a/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/MetaProvider.cs b/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/MetaProvider.cs
index 4bc2aafd..91446c33 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/MetaProvider.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/MetaProvider.cs
@@ -28,8 +28,7 @@ namespace QuickLook.Plugin.ImageViewer;
 
 public class MetaProvider
 {
-    private readonly SortedDictionary<string, (string, string)> _cache =
-        new SortedDictionary<string, (string, string)>(); // [key, [label, value]]
+    private readonly SortedDictionary<string, (string, string)> _cache = []; // [key, [label, value]]
 
     private readonly string _path;