From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Minecrell <minecrell@minecrell.net>
Date: Thu, 21 Sep 2017 19:41:20 +0200
Subject: [PATCH] Add workaround for plugins modifying the parent of the plugin
 logger

Essentials uses a custom logger name ("Essentials") instead of the
plugin logger. Log messages are redirected to the plugin logger by
setting the parent of the "Essentials" logger to the plugin logger.

With our changes, the plugin logger is now also called "Essentials",
resulting in an infinite loop. Make sure plugins can't change the
parent of the plugin logger to avoid this.

diff --git a/src/main/java/com/destroystokyo/paper/utils/PaperPluginLogger.java b/src/main/java/com/destroystokyo/paper/utils/PaperPluginLogger.java
new file mode 100644
index 0000000000000000000000000000000000000000..087ee57fe5485bc760fadd45a176d4d90a18f9f8
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/utils/PaperPluginLogger.java
@@ -0,0 +1,48 @@
+package com.destroystokyo.paper.utils;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import org.bukkit.plugin.PluginDescriptionFile;
+
+import java.util.logging.Level;
+import java.util.logging.LogManager;
+import java.util.logging.Logger;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Prevents plugins (e.g. Essentials) from changing the parent of the plugin logger.
+ */
+public class PaperPluginLogger extends Logger {
+
+    @Deprecated(forRemoval = true)
+    @NotNull
+    public static Logger getLogger(@NotNull PluginDescriptionFile description) {
+        return getLogger((PluginMeta) description);
+    }
+
+    @NotNull
+    public static Logger getLogger(@NotNull PluginMeta meta) {
+        Logger logger = new PaperPluginLogger(meta);
+        if (!LogManager.getLogManager().addLogger(logger)) {
+            // Disable this if it's going to happen across reloads anyways...
+            //logger.log(Level.WARNING, "Could not insert plugin logger - one was already found: {}", LogManager.getLogManager().getLogger(this.getName()));
+            logger = LogManager.getLogManager().getLogger(meta.getLoggerPrefix() != null ? meta.getLoggerPrefix() : meta.getName());
+        }
+
+        return logger;
+    }
+
+    private PaperPluginLogger(@NotNull PluginMeta meta) {
+        super(meta.getLoggerPrefix() != null ? meta.getLoggerPrefix() : meta.getName(), null);
+    }
+
+    @Override
+    public void setParent(@NotNull Logger parent) {
+        if (getParent() != null) {
+            warning("Ignoring attempt to change parent of plugin logger");
+        } else {
+            this.log(Level.FINE, "Setting plugin logger parent to {0}", parent);
+            super.setParent(parent);
+        }
+    }
+
+}
diff --git a/src/main/java/org/bukkit/plugin/java/JavaPlugin.java b/src/main/java/org/bukkit/plugin/java/JavaPlugin.java
index 7cd9f98c042dc2bb80876af35c755f81bef34651..5cd236965de12392d8c7aa81307c0ff1cc8673b1 100644
--- a/src/main/java/org/bukkit/plugin/java/JavaPlugin.java
+++ b/src/main/java/org/bukkit/plugin/java/JavaPlugin.java
@@ -291,10 +291,10 @@ public abstract class JavaPlugin extends PluginBase {
             .orElseThrow();
     }
     public final void init(@NotNull PluginLoader loader, @NotNull Server server, @NotNull PluginDescriptionFile description, @NotNull File dataFolder, @NotNull File file, @NotNull ClassLoader classLoader) {
-        init(server, description, dataFolder, file, classLoader, description);
+        init(server, description, dataFolder, file, classLoader, description, com.destroystokyo.paper.utils.PaperPluginLogger.getLogger(description));
         this.pluginMeta = description;
     }
-    public final void init(@NotNull Server server, @NotNull PluginDescriptionFile description, @NotNull File dataFolder, @NotNull File file, @NotNull ClassLoader classLoader, @Nullable io.papermc.paper.plugin.configuration.PluginMeta configuration) {
+    public final void init(@NotNull Server server, @NotNull PluginDescriptionFile description, @NotNull File dataFolder, @NotNull File file, @NotNull ClassLoader classLoader, @Nullable io.papermc.paper.plugin.configuration.PluginMeta configuration, @NotNull Logger logger) {
     // Paper end
         this.loader = DummyPluginLoaderImplHolder.INSTANCE; // Paper
         this.server = server;
@@ -304,7 +304,7 @@ public abstract class JavaPlugin extends PluginBase {
         this.classLoader = classLoader;
         this.configFile = new File(dataFolder, "config.yml");
         this.pluginMeta = configuration; // Paper
-        this.logger = Logger.getLogger(description.getPrefix() != null ? description.getPrefix() : description.getName()); // Paper - Handle plugin prefix in implementation
+        this.logger = logger; // Paper
     }
 
     /**
diff --git a/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java b/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
index 58d20eff7e0da2d7fcb1609d55e4284715355634..8c5597e02d71c8db66e9cd11f0a41776eb471c46 100644
--- a/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java
@@ -67,6 +67,7 @@ public final class PluginClassLoader extends URLClassLoader implements io.paperm
         this.url = file.toURI().toURL();
         this.libraryLoader = libraryLoader;
 
+        this.logger = com.destroystokyo.paper.utils.PaperPluginLogger.getLogger(description); // Paper - Register logger early
         // Paper start
         this.dependencyContext = dependencyContext;
         this.classLoaderGroup = io.papermc.paper.plugin.provider.classloader.PaperClassLoaderStorage.instance().registerSpigotGroup(this);
@@ -262,7 +263,7 @@ public final class PluginClassLoader extends URLClassLoader implements io.paperm
         pluginState = new IllegalStateException("Initial initialization");
         this.pluginInit = javaPlugin;
 
-        javaPlugin.init(null, org.bukkit.Bukkit.getServer(), description, dataFolder, file, this); // Paper
+        javaPlugin.init(org.bukkit.Bukkit.getServer(), description, dataFolder, file, this, description, this.logger); // Paper
     }
 
     // Paper start
