From 9f304bda4f0740cb0f7631a805a14dd17a88637b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20N=C3=BCcke?= <florian@nuecke.de>
Date: Fri, 8 Aug 2014 22:51:38 +0200
Subject: [PATCH] Made power support more stable (checking if methods are
 implemented before injecting the interfaces, to prevent crashes if APIs
 change, e.g.)

---
 .../li/cil/oc/common/asm/ClassTransformer.scala    | 14 +++++++++++++-
 src/main/scala/li/cil/oc/util/mods/Mods.scala      |  6 ++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/main/scala/li/cil/oc/common/asm/ClassTransformer.scala b/src/main/scala/li/cil/oc/common/asm/ClassTransformer.scala
index 2de8f0dbb..5e3cdb21c 100644
--- a/src/main/scala/li/cil/oc/common/asm/ClassTransformer.scala
+++ b/src/main/scala/li/cil/oc/common/asm/ClassTransformer.scala
@@ -64,8 +64,20 @@ class ClassTransformer extends IClassTransformer {
 
           // Inject available power interfaces into power acceptors.
           if (classNode.interfaces.contains("li/cil/oc/common/tileentity/traits/PowerAcceptor")) {
+            def missingImplementations(interfaceName: String) = {
+              val node = classNodeFor(interfaceName)
+              if (node == null) Seq(s"Interface ${interfaceName.replaceAll("/", ".")} not found.")
+              else node.methods.filterNot(im => classNode.methods.exists(cm => im.name == cm.name && im.desc == cm.desc)).map(method => s"Missing implementation of ${method.name + method.desc}")
+            }
             for ((mod, interfaces) <- powerTypes if mod.isAvailable) {
-              interfaces.foreach(classNode.interfaces.add)
+              val missing = interfaces.flatMap(missingImplementations)
+              if (missing.isEmpty) {
+                interfaces.foreach(classNode.interfaces.add)
+              }
+              else {
+                log.warning(s"Skipping power support for mod ${mod.id}.")
+                missing.foreach(log.warning)
+              }
             }
           }
 
diff --git a/src/main/scala/li/cil/oc/util/mods/Mods.scala b/src/main/scala/li/cil/oc/util/mods/Mods.scala
index 5c3a8132f..b99c5efb0 100644
--- a/src/main/scala/li/cil/oc/util/mods/Mods.scala
+++ b/src/main/scala/li/cil/oc/util/mods/Mods.scala
@@ -49,6 +49,8 @@ object Mods {
     })
   }
   val ComputerCraft = new Mod {
+    def id = IDs.ComputerCraft
+
     override def isAvailable = ComputerCraft15.isAvailable || ComputerCraft16.isAvailable
   }
   val Factorization = new SimpleMod(IDs.Factorization, providesPower = true)
@@ -63,6 +65,8 @@ object Mods {
   val ProjectRedTransmission = new SimpleMod(IDs.ProjectRedTransmission)
   val RedLogic = new SimpleMod(IDs.RedLogic)
   val StargateTech2 = new Mod {
+    def id = IDs.StargateTech2
+
     val isAvailable = Loader.isModLoaded(IDs.StargateTech2) && {
       val mod = Loader.instance.getIndexedModList.get(IDs.StargateTech2)
       mod.getVersion.startsWith("0.7.")
@@ -78,6 +82,8 @@ object Mods {
   trait Mod {
     knownMods += this
 
+    def id: String
+
     def isAvailable: Boolean
 
     def providesPower: Boolean = false