Bump version number, and add new transformer that adds synthetic <init> methods to inner classes.

Mojang's current snapshots include inner classes that are never initalized, so ProGuard removes the <init> methods.
We must re-add them so that FernFlower can detect the synthetic parent instance for proper decompilation.

Author: LexManos

build.gradle

@@ -13,7 +13,7 @@ apply plugin: 'fatjar'
 apply plugin: 'maven'
 
 group = 'de.oceanlabs.mcp'
-version = '3.4-SNAPSHOT'
+version = '3.5-SNAPSHOT'
 targetCompatibility = '1.6'
 sourceCompatibility = '1.6'
 

src/main/java/de/oceanlabs/mcp/mcinjector/MCInjectorImpl.java

@@ -43,6 +43,7 @@
 import de.oceanlabs.mcp.mcinjector.adaptors.ApplyMap;
 import de.oceanlabs.mcp.mcinjector.adaptors.ApplyMarker;
 import de.oceanlabs.mcp.mcinjector.adaptors.GenerateMap;
+import de.oceanlabs.mcp.mcinjector.adaptors.InnerClassInitAdder;
 import de.oceanlabs.mcp.mcinjector.adaptors.JsonAttribute;
 import de.oceanlabs.mcp.mcinjector.adaptors.LVTFernflower;
 import de.oceanlabs.mcp.mcinjector.adaptors.LVTLvt;
@@ -640,6 +641,8 @@ public byte[] processClass(byte[] cls, boolean readOnly)
         }
         ca = new AccessReader(ca, this);
 
+        ca = new InnerClassInitAdder(ca);
+
         cr.accept(ca, 0);
 
         ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);

src/main/java/de/oceanlabs/mcp/mcinjector/adaptors/InnerClassInitAdder.java

@@ -0,0 +1,77 @@
+package de.oceanlabs.mcp.mcinjector.adaptors;
+
+import static org.objectweb.asm.Opcodes.*;
+
+import java.util.logging.Logger;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+public class InnerClassInitAdder extends ClassVisitor
+{
+    private static final Logger log = Logger.getLogger("MCInjector");
+    private String className, parentName, parentField;
+    private boolean hasInit = false;
+    private boolean isStatic = false;
+    private int FIELD_ACCESS = ACC_FINAL | ACC_SYNTHETIC;
+
+    public InnerClassInitAdder(ClassVisitor cv)
+    {
+        super(Opcodes.ASM5, cv);
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces)
+    {
+        this.isStatic = (access & ACC_STATIC) != 0;
+        this.className = name;
+        super.visit(version, access, name, signature, superName, interfaces);
+    }
+
+    @Override // The reader *should* read this before any fields/methods, so we can set the parent name to find the field
+    public void visitInnerClass(String name, String outerName, String innerName, int access)
+    {
+        if (this.className.equals(name))
+        {
+            this.parentName = "L" + outerName + ";";
+        }
+        super.visitInnerClass(name, outerName, innerName, access);
+    }
+
+    @Override
+    public FieldVisitor visitField(int access, String name, String desc, String signature, Object value)
+    {
+        if ((access & FIELD_ACCESS) == FIELD_ACCESS && desc.equals(this.parentName))
+        {
+            this.parentField = name;
+        }
+        return super.visitField(access, name, desc, signature, value);
+    }
+
+    @Override
+    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions)
+    {
+        if ("<init>".equals(name))
+        {
+            hasInit = true;
+        }
+        return super.visitMethod(access, name, desc, signature, exceptions);
+    }
+
+    @Override
+    public void visitEnd()
+    {
+        if (!hasInit && !isStatic && parentName != null && parentField != null)
+        {
+            log.fine("  Adding synthetic <init> " + parentName + " " + parentField);
+            MethodVisitor mv = this.visitMethod(ACC_PRIVATE | ACC_SYNTHETIC, "<init>", "(" + parentName + ")V", null, null);
+            mv.visitVarInsn(ALOAD, 0);
+            mv.visitVarInsn(ALOAD, 1);
+            mv.visitFieldInsn(PUTFIELD, className, parentField, parentName);
+            mv.visitInsn(RETURN);
+        }
+        super.visitEnd();
+    }
+}