Fix bad classloading for ProtocolLib

Author: InitAuther97

arclight-common/src/main/java/io/izzel/arclight/common/mod/util/remapper/ClassLoaderAdapter.java

@@ -114,7 +114,7 @@ private void implementIntf(ClassNode node) {
             list.add(new TypeInsnNode(Opcodes.NEW, config));
             list.add(new InsnNode(Opcodes.DUP));
             list.add(new VarInsnNode(Opcodes.ALOAD, 0));
-            list.add(new MethodInsnNode(Opcodes.INVOKESTATIC, Type.getInternalName(RemappingClassLoader.class), "needRemap", Type.getMethodDescriptor(Type.getType(boolean.class), Type.getType(ClassLoader.class))));
+            list.add(new MethodInsnNode(Opcodes.INVOKESTATIC, node.name, "needRemap", Type.getMethodDescriptor(Type.getType(boolean.class), Type.getType(ClassLoader.class))));
             list.add(new MethodInsnNode(Opcodes.INVOKESPECIAL, config, "<init>", "(Z)V"));
             list.add(new VarInsnNode(Opcodes.ALOAD, 0));
             list.add(new InsnNode(Opcodes.SWAP));
@@ -134,6 +134,7 @@ private void implementIntf(ClassNode node) {
         node.fields.add(remapper);
         node.fields.add(remapConfig);
         node.methods.add(getRemapper);
+        RemappingClassLoader.implementNeedRemap(node);
         node.methods.add(getConfig);
         node.interfaces.add(Type.getInternalName(RemappingClassLoader.class));
     }

arclight-common/src/main/java/io/izzel/arclight/common/mod/util/remapper/RemappingClassLoader.java

@@ -1,5 +1,9 @@
 package io.izzel.arclight.common.mod.util.remapper;
 
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.tree.*;
+
 public interface RemappingClassLoader {
 
     ClassLoaderRemapper getRemapper();
@@ -18,16 +22,73 @@ static boolean needRemap(ClassLoader cl) {
         // Removing redirect for PlatformClassLoader since only classes
         // in the standard library are loaded by PlatformClassLoader.
         // They are always related only to JDK we're using.
-        var now = cl;
-        final var needed = RemappingClassLoader.class.getClassLoader();
-        do {
-            if (now == ClassLoader.getSystemClassLoader() || now == needed) {
+        for (; cl != null; cl = cl.getParent()) {
+            if (cl == ClassLoader.getSystemClassLoader()) {
                 return true;
-            } else if (now == ClassLoader.getPlatformClassLoader() || now == null) {
-                return false;
             }
-            now = now.getParent();
-        } while (now != null);
+        }
         return false;
     }
+
+    // Bytecode version of the above code
+    static void implementNeedRemap(ClassNode node) {
+        MethodNode needRemap = new MethodNode(
+                Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC | Opcodes.ACC_SYNTHETIC,
+                "needRemap",
+                Type.getMethodDescriptor(Type.getType(boolean.class), Type.getType(ClassLoader.class)),
+                null, null
+        );
+        var l = needRemap.instructions;
+        {
+            var label0 = new LabelNode();
+            l.add(label0);
+            l.add(new LineNumberNode(-101, label0));
+            if (node.version >= Opcodes.V1_6) {
+                l.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
+            }
+            l.add(new VarInsnNode(Opcodes.ALOAD, 0));
+
+            var label1 = new LabelNode();
+            l.add(new JumpInsnNode(Opcodes.IFNULL, label1));
+
+            var label2 = new LabelNode();
+            l.add(label2);
+            l.add(new LineNumberNode(-102, label2));
+            l.add(new VarInsnNode(Opcodes.ALOAD, 0));
+            l.add(new MethodInsnNode(Opcodes.INVOKESTATIC, "java/lang/ClassLoader", "getSystemClassLoader", "()Ljava/lang/ClassLoader;", false));
+
+            var label3 = new LabelNode();
+            l.add(new JumpInsnNode(Opcodes.IF_ACMPNE, label3));
+
+            var label4 = new LabelNode();
+            l.add(label4);
+            l.add(new LineNumberNode(-103, label4));
+            l.add(new InsnNode(Opcodes.ICONST_1));
+            l.add(new InsnNode(Opcodes.IRETURN));
+
+            l.add(label3);
+            l.add(new LineNumberNode(-101, label3));
+            if (node.version >= Opcodes.V1_6) {
+                l.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
+            }
+            l.add(new VarInsnNode(Opcodes.ALOAD, 0));
+            l.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, "java/lang/ClassLoader", "getParent", "()Ljava/lang/ClassLoader;", false));
+            l.add(new VarInsnNode(Opcodes.ASTORE, 0));
+            l.add(new JumpInsnNode(Opcodes.GOTO, label0));
+
+            l.add(label1);
+            l.add(new LineNumberNode(-106, label1));
+            if (node.version >= Opcodes.V1_6) {
+                l.add(new FrameNode(Opcodes.F_SAME, 0, null, 0, null));
+            }
+            l.add(new InsnNode(Opcodes.ICONST_0));
+            l.add(new InsnNode(Opcodes.IRETURN));
+
+            var label5 = new LabelNode();
+            l.add(label5);
+            needRemap.localVariables.add(new LocalVariableNode("cl", "Ljava/lang/ClassLoader;", null, label0, label5, 0));
+        }
+        needRemap.visitMaxs(2, 1);
+        node.methods.add(needRemap);
+    }
 }