From ce552ff99de94b84e93da84007c0aad2e36bcbd1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20N=C3=BCcke?= <florian@nuecke.de>
Date: Tue, 21 Apr 2015 12:02:02 +0200
Subject: [PATCH] Should avoid unexpected error if trying to `tostring` a
 method that's now filtered out. Clearing out callback cache when a world is
 unloaded.

---
 src/main/scala/li/cil/oc/common/EventHandler.scala          | 3 +++
 src/main/scala/li/cil/oc/server/machine/Callbacks.scala     | 6 ++++++
 .../scala/li/cil/oc/server/machine/luac/ComponentAPI.scala  | 2 +-
 .../scala/li/cil/oc/server/machine/luaj/ComponentAPI.scala  | 2 +-
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/main/scala/li/cil/oc/common/EventHandler.scala b/src/main/scala/li/cil/oc/common/EventHandler.scala
index 7d69d7126..28e8a5d8f 100644
--- a/src/main/scala/li/cil/oc/common/EventHandler.scala
+++ b/src/main/scala/li/cil/oc/common/EventHandler.scala
@@ -25,6 +25,7 @@ import li.cil.oc.common.tileentity.traits.power
 import li.cil.oc.integration.Mods
 import li.cil.oc.integration.util
 import li.cil.oc.server.component.Keyboard
+import li.cil.oc.server.machine.Callbacks
 import li.cil.oc.server.machine.Machine
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import li.cil.oc.util.ExtendedWorld._
@@ -357,6 +358,8 @@ object EventHandler {
       e.world.loadedEntityList.collect {
         case host: MachineHost => host.machine.stop()
       }
+
+      Callbacks.clear()
     }
   }
 
diff --git a/src/main/scala/li/cil/oc/server/machine/Callbacks.scala b/src/main/scala/li/cil/oc/server/machine/Callbacks.scala
index c86f58f04..069a3048b 100644
--- a/src/main/scala/li/cil/oc/server/machine/Callbacks.scala
+++ b/src/main/scala/li/cil/oc/server/machine/Callbacks.scala
@@ -27,6 +27,12 @@ object Callbacks {
     case _ => cache.getOrElseUpdate(host.getClass, dynamicAnalyze(host))
   }
 
+  // Clear the cache; used when world is unloaded, mostly to allow reacting to
+  // stuff (aka configs) that may influence which @Callbacks are enabled.
+  def clear(): Unit = {
+    cache.clear()
+  }
+
   def fromClass(environment: Class[_]) = staticAnalyze(environment)
 
   private def dynamicAnalyze(host: Any) = {
diff --git a/src/main/scala/li/cil/oc/server/machine/luac/ComponentAPI.scala b/src/main/scala/li/cil/oc/server/machine/luac/ComponentAPI.scala
index 5d020153b..8c724ff7a 100644
--- a/src/main/scala/li/cil/oc/server/machine/luac/ComponentAPI.scala
+++ b/src/main/scala/li/cil/oc/server/machine/luac/ComponentAPI.scala
@@ -83,7 +83,7 @@ class ComponentAPI(owner: NativeLuaArchitecture) extends NativeLuaAPI(owner) {
       withComponent(lua.checkString(1), component => {
         val method = lua.checkString(2)
         val methods = machine.methods(component.host)
-        owner.documentation(() => methods(method).doc)
+        owner.documentation(() => Option(methods.get(method)).map(_.doc).orNull)
       })
     })
     lua.setField(-2, "doc")
diff --git a/src/main/scala/li/cil/oc/server/machine/luaj/ComponentAPI.scala b/src/main/scala/li/cil/oc/server/machine/luaj/ComponentAPI.scala
index 34cfbff2c..8dfe93e41 100644
--- a/src/main/scala/li/cil/oc/server/machine/luaj/ComponentAPI.scala
+++ b/src/main/scala/li/cil/oc/server/machine/luaj/ComponentAPI.scala
@@ -71,7 +71,7 @@ class ComponentAPI(owner: LuaJLuaArchitecture) extends LuaJAPI(owner) {
       withComponent(args.checkjstring(1), component => {
         val method = args.checkjstring(2)
         val methods = machine.methods(component.host)
-        owner.documentation(() => methods(method).doc)
+        owner.documentation(() => Option(methods.get(method)).map(_.doc).orNull)
       })
     })