From 7719039473d649fadf7f36269f4d6fb979037978 Mon Sep 17 00:00:00 2001
From: Runemoro <runemoro@live.ca>
Date: Wed, 20 Jun 2018 18:45:52 -0400
Subject: [PATCH] Overriding methods can return a superclass of the method they
 override

---
 .../javaremapper/GeneratingMapping.java       | 31 +-----------------
 .../dimdev/javaremapper/SimpleRemapper.java   | 18 ++++++-----
 .../org/dimdev/javaremapper/TypeUtil.java     | 32 +++++++++++++++++++
 3 files changed, 43 insertions(+), 38 deletions(-)
 create mode 100644 src/main/java/org/dimdev/javaremapper/TypeUtil.java

diff --git a/src/main/java/org/dimdev/javaremapper/GeneratingMapping.java b/src/main/java/org/dimdev/javaremapper/GeneratingMapping.java
index 31b3361..3db6d7c 100644
--- a/src/main/java/org/dimdev/javaremapper/GeneratingMapping.java
+++ b/src/main/java/org/dimdev/javaremapper/GeneratingMapping.java
@@ -1,7 +1,5 @@
 package org.dimdev.javaremapper;
 
-import org.objectweb.asm.Type;
-
 import java.util.Set;
 
 public class GeneratingMapping extends Mapping {
@@ -61,7 +59,7 @@ public String getMethod(String className, String methodName, String methodDescri
         // Don't remap inherited methods, their name is inherited from the parent's mapping
         for (String superclass : inheritanceProvider.getAllSuperclasses(className)) {
             for (MemberRef ref : inheritanceProvider.getInheritableMethods(superclass)) {
-                if (methodName.equals(ref.name) && methodDescriptorOverrides(methodDescriptor, ref.descriptor)) {
+                if (methodName.equals(ref.name) && TypeUtil.methodDescriptorOverrides(inheritanceProvider, methodDescriptor, ref.descriptor)) {
                     return null;
                 }
             }
@@ -74,31 +72,4 @@ public String getMethod(String className, String methodName, String methodDescri
         }
         return result;
     }
-
-    private boolean methodDescriptorOverrides(String descriptor1, String descriptor2) {
-        // Check return types
-        Type ret1 = Type.getReturnType(descriptor1);
-        Type ret2 = Type.getReturnType(descriptor2);
-        if (!ret1.equals(ret2) && !inheritanceProvider.getAllSuperclasses(ret1.getClassName()).contains(ret2.getClassName())) {
-            return false;
-        }
-
-        // Check argument types
-        Type[] args1 = Type.getArgumentTypes(descriptor1);
-        Type[] args2 = Type.getArgumentTypes(descriptor2);
-
-        if (args1.length != args2.length) return false;
-
-        for (int i = 0; i < args1.length; i++) {
-            String class1 = args1[i].getClassName();
-            String class2 = args2[i].getClassName();
-
-            // Arguments must be the identical in Java, not supertypes
-            if (!class1.equals(class2)) {
-                return false;
-            }
-        }
-
-        return true;
-    }
 }
diff --git a/src/main/java/org/dimdev/javaremapper/SimpleRemapper.java b/src/main/java/org/dimdev/javaremapper/SimpleRemapper.java
index 523b811..4c2f600 100644
--- a/src/main/java/org/dimdev/javaremapper/SimpleRemapper.java
+++ b/src/main/java/org/dimdev/javaremapper/SimpleRemapper.java
@@ -42,15 +42,17 @@ public String mapMethodName(String owner, String name, String desc) {
         String newName = mapping.getMethod(owner, name, desc);
 
         for (String superclass : inheritanceProvider.getAllSuperclasses(owner)) {
-            if (inheritanceProvider.getInheritableMethods(superclass).contains(new MemberRef(name, desc))) {
-                String inheritedNewName = mapping.getMethod(superclass, name, desc);
-                if (inheritedNewName != null) {
-                    if (newName != null && !inheritedNewName.equals(newName)) {
-                        System.err.println("Method inheritance problem: " + owner + "." + name + desc +
-                                           " inherits " + superclass + "." + name + desc +
-                                           " but " + newName + " != " + inheritedNewName);
+            for (MemberRef ref : inheritanceProvider.getInheritableMethods(superclass)) {
+                if (name.equals(ref.name) && TypeUtil.methodDescriptorOverrides(inheritanceProvider, desc, ref.descriptor)) {
+                    String inheritedNewName = mapping.getMethod(superclass, name, desc);
+                    if (inheritedNewName != null) {
+                        if (newName != null && !inheritedNewName.equals(newName)) {
+                            System.err.println("Method inheritance problem: " + owner + "." + name + desc +
+                                               " inherits " + superclass + "." + name + desc +
+                                               " but " + newName + " != " + inheritedNewName);
+                        }
+                        return inheritedNewName;
                     }
-                    return inheritedNewName;
                 }
             }
         }
diff --git a/src/main/java/org/dimdev/javaremapper/TypeUtil.java b/src/main/java/org/dimdev/javaremapper/TypeUtil.java
new file mode 100644
index 0000000..1d021e9
--- /dev/null
+++ b/src/main/java/org/dimdev/javaremapper/TypeUtil.java
@@ -0,0 +1,32 @@
+package org.dimdev.javaremapper;
+
+import org.objectweb.asm.Type;
+
+public final class TypeUtil {
+    public static boolean methodDescriptorOverrides(InheritanceProvider inheritanceProvider, String descriptor1, String descriptor2) {
+        // Check return types
+        Type ret1 = Type.getReturnType(descriptor1);
+        Type ret2 = Type.getReturnType(descriptor2);
+        if (!ret1.equals(ret2) && !inheritanceProvider.getAllSuperclasses(ret1.getClassName()).contains(ret2.getClassName())) {
+            return false;
+        }
+
+        // Check argument types
+        Type[] args1 = Type.getArgumentTypes(descriptor1);
+        Type[] args2 = Type.getArgumentTypes(descriptor2);
+
+        if (args1.length != args2.length) return false;
+
+        for (int i = 0; i < args1.length; i++) {
+            String class1 = args1[i].getClassName();
+            String class2 = args2[i].getClassName();
+
+            // Arguments must be the identical in Java, not supertypes
+            if (!class1.equals(class2)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}