fixed double-loading of plugins.

2 files changed, 6 insertions, 6 deletions

diff --git a/src/compiler/scala/tools/nsc/plugins/Plugin.scala b/src/compiler/scala/tools/nsc/plugins/Plugin.scala
index 92dcd6c534..f527441c68 100644
--- a/src/compiler/scala/tools/nsc/plugins/Plugin.scala
+++ b/src/compiler/scala/tools/nsc/plugins/Plugin.scala
@@ -131,13 +131,13 @@ object Plugin {
     dirs: List[Path],
     ignoring: List[String]): List[AnyClass] =
   {
-    val alljars = jars ::: (for {
+    val alljars = (jars ::: (for {
       dir <- dirs if dir.isDirectory
       entry <- dir.toDirectory.files.toList sortBy (_.name)
       if entry.extension == "jar"
       pdesc <- loadDescription(entry)
       if !(ignoring contains pdesc.name)
-    } yield entry)
+    } yield entry)).distinct
 
     val loader = loaderFor(alljars)
     alljars map (loadFrom(_, loader)) flatten
diff --git a/src/compiler/scala/tools/nsc/plugins/Plugins.scala b/src/compiler/scala/tools/nsc/plugins/Plugins.scala
index 90d306614a..8a86c982d9 100644
--- a/src/compiler/scala/tools/nsc/plugins/Plugins.scala
+++ b/src/compiler/scala/tools/nsc/plugins/Plugins.scala
@@ -30,10 +30,10 @@ trait Plugins
     val dirs = (settings.pluginsDir.value split File.pathSeparator).toList map Path.apply
     val classes = Plugin.loadAllFrom(jars, dirs, settings.disable.value)
 
-    classes foreach (c => Plugin.instantiate(c, this))
-
-    for (plugClass <- Plugin.loadAllFrom(jars, dirs, settings.disable.value))
-    yield Plugin.instantiate(plugClass, this)
+    // Lach plugin must only be instantiated once. A commong pattern
+    // is to register annotation checkers during object construction, so
+    // creating multiple plugin instances will leave behind stale checkers. s
+    classes map (Plugin.instantiate(_, this))
   }
 
   protected lazy val roughPluginsList: List[Plugin] = loadRoughPluginsList