Fixes merged ModuleID dropping configuration specification. Fixes #2002/#1500

Given a dependency graph such as:

    libraryDependencies += "com.google.guava" % "guava-tests" % "18.0"
    libraryDependencies += "com.google.guava" % "guava-tests" % "18.0"
% "test" classifier "tests"

previous releases of sbt would drop the Test configuration from the
classifier "tests" artifacts, and end up including the test JARs into
the Compile configuration instead of the Test configuration, which
would result in runtime error.

This fix configures the explicit artifacts into the configuration
during merge even when it says `"*"`.

ivy/src/main/scala/sbt/ivyint/MergeDescriptors.scala

@@ -38,7 +38,7 @@ private[sbt] object MergeDescriptors {
 
 // combines the artifacts, configurations, includes, and excludes for DependencyDescriptors `a` and `b`
 // that otherwise have equal IDs
-private final class MergedDescriptors(a: DependencyDescriptor, b: DependencyDescriptor) extends DependencyDescriptor {
+private[sbt] final case class MergedDescriptors(a: DependencyDescriptor, b: DependencyDescriptor) extends DependencyDescriptor {
   def getDependencyId = a.getDependencyId
   def isForce = a.isForce
   def isChanging = a.isChanging
@@ -87,11 +87,14 @@ private final class MergedDescriptors(a: DependencyDescriptor, b: DependencyDesc
     arts map { art => explicitConfigurations(base, art) }
   private[this] def explicitConfigurations(base: DependencyDescriptor, art: DependencyArtifactDescriptor): DependencyArtifactDescriptor =
     {
-      val aConfs = art.getConfigurations
-      if (aConfs == null || aConfs.isEmpty)
-        copyWithConfigurations(art, base.getModuleConfigurations)
-      else
-        art
+      val aConfs = Option(art.getConfigurations) map { _.toList }
+      // In case configuration list is "*", we should still specify the module configuration of the DependencyDescriptor
+      // otherwise the explicit specified artifacts from one dd can leak over to the other.
+      // See gh-1500, gh-2002
+      aConfs match {
+        case None | Some(Nil) | Some(List("*")) => copyWithConfigurations(art, base.getModuleConfigurations)
+        case _                                  => art
+      }
     }
   private[this] def defaultArtifact(a: DependencyDescriptor): Array[DependencyArtifactDescriptor] =
     {

ivy/src/test/scala/MergeDescriptorSpec.scala

@@ -0,0 +1,42 @@
+package sbt
+
+import sbt.ivyint.MergedDescriptors
+import org.specs2._
+import org.apache.ivy.core.module.descriptor.{ DependencyArtifactDescriptor, DependencyDescriptor }
+
+class MergeDescriptorSpec extends BaseIvySpecification {
+  def is = args(sequential = true) ^ s2"""
+
+  This is a specification to check the merge descriptor
+
+  Merging duplicate dependencies should
+    work                                                        $e1
+                                                                """
+
+  def guavaTest = ModuleID("com.google.guava", "guava-tests", "18.0", configurations = Some("compile"))
+  def guavaTestTests = ModuleID("com.google.guava", "guava-tests", "18.0", configurations = Some("test")).classifier("tests")
+  def defaultOptions = EvictionWarningOptions.default
+
+  import ShowLines._
+
+  def e1 = {
+    cleanIvyCache()
+    val m = module(ModuleID("com.example", "foo", "0.1.0", Some("compile")),
+      Seq(guavaTest, guavaTestTests), None, UpdateOptions())
+    m.withModule(log) {
+      case (ivy, md, _) =>
+        val deps = md.getDependencies
+        assert(deps.size == 1)
+        deps.head match {
+          case dd @ MergedDescriptors(dd0, dd1) =>
+            val arts = dd.getAllDependencyArtifacts
+            val a0: DependencyArtifactDescriptor = arts.toList(0)
+            val a1: DependencyArtifactDescriptor = arts.toList(1)
+            val configs0 = a0.getConfigurations.toList
+            val configs1 = a1.getConfigurations.toList
+            (configs0 must_== List("compile")) and
+              (configs1 must_== List("test"))
+        }
+    }
+  }
+}

notes/0.13.12/merge-descriptor-fix.md

@@ -0,0 +1,7 @@
+  [@eed3si9n]: https://github.com/eed3si9n
+  [1500]: https://github.com/sbt/sbt/issues/1500
+  [2002]: https://github.com/sbt/sbt/issues/2002
+
+### Bug fixes
+
+- Fixes merged dependency descriptors dropping configuration specification. [#2002][2005]/[#1500][1500] by [@eed3si9n][@eed3si9n]