Prevent servers from fingerprinting you via the resource pack cache.

This allowed servers to track users even if they changed accounts.

See: https://alaggydev.github.io/posts/cytooxien
See: CCBlueX/LiquidBounce#7007

Author: Wide-Cat

src/main/java/meteordevelopment/meteorclient/mixin/DownloaderMixin.java

@@ -0,0 +1,46 @@
+/*
+ * This file is part of the Meteor Client distribution (https://github.com/MeteorDevelopment/meteor-client).
+ * Copyright (c) Meteor Development.
+ */
+
+package meteordevelopment.meteorclient.mixin;
+
+import com.llamalad7.mixinextras.injector.ModifyExpressionValue;
+import com.llamalad7.mixinextras.sugar.Local;
+import meteordevelopment.meteorclient.MeteorClient;
+import net.minecraft.util.Downloader;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+
+import java.nio.file.Path;
+import java.util.UUID;
+
+import static meteordevelopment.meteorclient.MeteorClient.mc;
+
+/**
+ * Taken from <a href="https://github.com/CCBlueX/LiquidBounce">LiquidBounce</a>
+ * <p>
+ * Copyright (c) 2021 - 2025 CCBlueX
+ *
+ * @author Izuna
+ * @see <a href="https://github.com/CCBlueX/LiquidBounce/blob/nextgen/src/main/java/net/ccbluex/liquidbounce/injection/mixins/minecraft/util/MixinDownloader.java">MixinDownloader.java</a>
+ */
+@Mixin(Downloader.class)
+public class DownloaderMixin {
+    @Shadow
+    @Final
+    private Path directory;
+
+    @ModifyExpressionValue(method = "method_55485", at = @At(value = "INVOKE", target = "Ljava/nio/file/Path;resolve(Ljava/lang/String;)Ljava/nio/file/Path;"))
+    private Path hookResolve(Path original, @Local(argsOnly = true) UUID id) {
+        UUID accountId = mc.getSession().getUuidOrNull();
+        if (accountId == null) {
+            MeteorClient.LOG.warn("Failed to change resource pack download directory because the account id is null.");
+            return original;
+        }
+
+        return directory.resolve(accountId.toString()).resolve(id.toString());
+    }
+}

src/main/resources/meteor-client.mixins.json

@@ -72,6 +72,7 @@
     "DefaultSkinHelperMixin",
     "DirectionAccessor",
     "DisconnectedScreenMixin",
+    "DownloaderMixin",
     "DrawContextMixin",
     "ElytraFeatureRendererMixin",
     "EnchantingTableBlockEntityRendererMixin",