From 236fa2126f7db27de4c9e16b8b77d7e8cfbe0e35 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Tue, 21 May 2024 13:18:00 -0700
Subject: [PATCH] Allow Bukkit plugin to use Paper PluginLoader API

---
 .../bukkit/plugin/PluginDescriptionFile.java  | 24 +++++++++++++++++++
 .../org/bukkit/plugin/java/LibraryLoader.java | 17 +++++++++----
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/paper-api/src/main/java/org/bukkit/plugin/PluginDescriptionFile.java b/paper-api/src/main/java/org/bukkit/plugin/PluginDescriptionFile.java
index d24dc9dfe1..6dfd519968 100644
--- a/paper-api/src/main/java/org/bukkit/plugin/PluginDescriptionFile.java
+++ b/paper-api/src/main/java/org/bukkit/plugin/PluginDescriptionFile.java
@@ -260,6 +260,13 @@ public final class PluginDescriptionFile implements io.papermc.paper.plugin.conf
     private Set<PluginAwareness> awareness = ImmutableSet.of();
     private String apiVersion = null;
     private List<String> libraries = ImmutableList.of();
+    // Paper start - plugin loader api
+    private String paperPluginLoader;
+    @org.jetbrains.annotations.ApiStatus.Internal @org.jetbrains.annotations.Nullable
+    public String getPaperPluginLoader() {
+        return this.paperPluginLoader;
+    }
+    // Paper end - plugin loader api
     // Paper start - oh my goddddd
     /**
      * Don't use this.
@@ -1233,6 +1240,23 @@ public final class PluginDescriptionFile implements io.papermc.paper.plugin.conf
         } else {
             libraries = ImmutableList.<String>of();
         }
+        // Paper start - plugin loader api
+        if (map.containsKey("paper-plugin-loader")) {
+            this.paperPluginLoader = map.get("paper-plugin-loader").toString();
+        }
+
+        /*
+        Allow skipping the Bukkit/Spigot 'libraries' list. By default, both the 'libraries'
+        list and the 'paper-plugin-loader' will contribute libraries. It may be desired to only
+        use one or the other. (i.e. 'libraries' on Spigot and 'paper-plugin-loader' on Paper)
+        */
+        if (map.containsKey("paper-skip-libraries")) {
+            String skip = map.get("paper-skip-libraries").toString();
+            if (skip.equalsIgnoreCase("true")) {
+                this.libraries = ImmutableList.of();
+            }
+        }
+        // Paper end - plugin loader api
 
         try {
             lazyPermissions = (Map<?, ?>) map.get("permissions");
diff --git a/paper-api/src/main/java/org/bukkit/plugin/java/LibraryLoader.java b/paper-api/src/main/java/org/bukkit/plugin/java/LibraryLoader.java
index 8e1b6be246..c66252802c 100644
--- a/paper-api/src/main/java/org/bukkit/plugin/java/LibraryLoader.java
+++ b/paper-api/src/main/java/org/bukkit/plugin/java/LibraryLoader.java
@@ -84,7 +84,13 @@ public class LibraryLoader
     @Nullable
     public ClassLoader createLoader(@NotNull PluginDescriptionFile desc)
     {
-        if ( desc.getLibraries().isEmpty() )
+        // Paper start - plugin loader api
+        return this.createLoader(desc, null);
+    }
+    @Nullable
+    public ClassLoader createLoader(@NotNull PluginDescriptionFile desc, java.util.@Nullable List<java.nio.file.Path> paperLibraryPaths) {
+        if ( desc.getLibraries().isEmpty() && paperLibraryPaths == null )
+        // Paper end - plugin loader api
         {
             return null;
         }
@@ -103,17 +109,20 @@ public class LibraryLoader
         }
 
         DependencyResult result;
-        try
+        if (!dependencies.isEmpty()) try // Paper - plugin loader api
         {
             result = repository.resolveDependencies( session, new DependencyRequest( new CollectRequest( (Dependency) null, dependencies, repositories ), null ) );
         } catch ( DependencyResolutionException ex )
         {
             throw new RuntimeException( "Error resolving libraries", ex );
-        }
+        } else result = null; // Paper - plugin loader api
 
         List<URL> jarFiles = new ArrayList<>();
         List<java.nio.file.Path> jarPaths = new ArrayList<>(); // Paper - remap libraries
-        for ( ArtifactResult artifact : result.getArtifactResults() )
+        // Paper start - plugin loader api
+        if (paperLibraryPaths != null) jarPaths.addAll(paperLibraryPaths);
+        if (result != null) for ( ArtifactResult artifact : result.getArtifactResults() )
+        // Paper end - plugin loader api
         {
             // Paper start - remap libraries
             jarPaths.add(artifact.getArtifact().getFile().toPath());