From e28e4514318add378fb4930291e5635177ced4c6 Mon Sep 17 00:00:00 2001
From: Dmitrii Naumenko <unkarjedy@mail.ru>
Date: Sat, 7 Sep 2019 23:26:13 +0300
Subject: [PATCH] remove duplicates from allJars when creating ScalaInstance
 #5052 (#5053)

Fixes #5052
---
 main/src/main/scala/sbt/Defaults.scala | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index a1c8443ac..4ec5ba97d 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -812,10 +812,12 @@ object Defaults extends BuildCommon {
       compilerJar: File,
       classLoaderCache: sbt.internal.inc.classpath.ClassLoaderCache
   ): ScalaInstance = {
+    val allJarsDistinct = allJars.distinct
     val libraryLoader = classLoaderCache(libraryJars.toList)
-    class ScalaLoader extends URLClassLoader(allJars.map(_.toURI.toURL).toArray, libraryLoader)
+    class ScalaLoader
+        extends URLClassLoader(allJarsDistinct.map(_.toURI.toURL).toArray, libraryLoader)
     val fullLoader = classLoaderCache.cachedCustomClassloader(
-      allJars.toList,
+      allJarsDistinct.toList,
       () => new ScalaLoader
     )
     new ScalaInstance(
@@ -824,7 +826,7 @@ object Defaults extends BuildCommon {
       libraryLoader,
       libraryJars,
       compilerJar,
-      allJars.toArray,
+      allJarsDistinct.toArray,
       Some(version)
     )
   }