From 6e0c6c35153c3be04cba4fc59767438f4ff5c28f Mon Sep 17 00:00:00 2001
From: Alexandre Archambault <alexandre.archambault@gmail.com>
Date: Mon, 15 May 2017 15:32:54 +0200
Subject: [PATCH] Always use same Function1 instance for Resolution fields

Allows to use the resolution as cache key
---
 sbt-coursier/src/main/scala/coursier/Tasks.scala | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/sbt-coursier/src/main/scala/coursier/Tasks.scala b/sbt-coursier/src/main/scala/coursier/Tasks.scala
index f5a1dab44..da58bafb8 100644
--- a/sbt-coursier/src/main/scala/coursier/Tasks.scala
+++ b/sbt-coursier/src/main/scala/coursier/Tasks.scala
@@ -425,6 +425,9 @@ object Tasks {
       }
     }
 
+  private val noOptionalFilter: Option[Dependency => Boolean] = Some(dep => !dep.optional)
+  private val typelevelOrgSwap: Option[Dependency => Dependency] = Some(Typelevel.swap(_))
+
 
   def resolutionTask(
     sbtClassifiers: Boolean = false
@@ -506,7 +509,7 @@ object Tasks {
 
       val startRes = Resolution(
         currentProject.dependencies.map(_._2).toSet,
-        filter = Some(dep => !dep.optional),
+        filter = noOptionalFilter,
         userActivations =
           if (userEnabledProfiles.isEmpty)
             None
@@ -518,7 +521,7 @@ object Tasks {
           forcedScalaModules(so, sv) ++
           interProjectDependencies.map(_.moduleVersion),
         projectCache = parentProjectCache,
-        mapDependencies = if (typelevel) Some(Typelevel.swap(_)) else None
+        mapDependencies = if (typelevel) typelevelOrgSwap else None
       )
 
       if (verbosityLevel >= 2) {
@@ -1060,7 +1063,7 @@ object Tasks {
       reportsCache.getOrElseUpdate(
         ReportCacheKey(
           currentProject,
-          res.copy(filter = None),
+          res,
           withClassifiers,
           sbtClassifiers
         ),