support delegating to a project with different configurations

main/Load.scala

@@ -59,7 +59,7 @@ object Load
 			case BuildRef(uri) => configInheritRef(lb, ProjectRef(uri, rootProject(uri)), config)
 		}
 	def configInheritRef(lb: LoadedBuild, ref: ProjectRef, config: ConfigKey): Seq[ConfigKey] =
-		getConfiguration(lb.units, ref.build, ref.project, config).extendsConfigs.map(c => ConfigKey(c.name))
+		configurationOpt(lb.units, ref.build, ref.project, config).toList.flatMap(_.extendsConfigs).map(c => ConfigKey(c.name))
 
 	def projectInherit(lb: LoadedBuild, ref: ResolvedReference): Seq[ProjectRef] =
 		ref match
@@ -282,7 +282,9 @@ object Load
 	def getRootProject(map: Map[URI, BuildUnitBase]): URI => String =
 		uri => getBuild(map, uri).rootProjects.headOption getOrElse emptyBuild(uri)
 	def getConfiguration(map: Map[URI, LoadedBuildUnit], uri: URI, id: String, conf: ConfigKey): Configuration =
-		getProject(map, uri, id).configurations.find(_.name == conf.name) getOrElse noConfiguration(uri, id, conf.name)
+		configurationOpt(map, uri, id, conf) getOrElse noConfiguration(uri, id, conf.name)
+	def configurationOpt(map: Map[URI, LoadedBuildUnit], uri: URI, id: String, conf: ConfigKey): Option[Configuration] =
+		getProject(map, uri, id).configurations.find(_.name == conf.name)
 
 	def getProject(map: Map[URI, LoadedBuildUnit], uri: URI, id: String): ResolvedProject =
 		getBuild(map, uri).defined.getOrElse(id, noProject(uri, id))

sbt/src/sbt-test/project/delegate_config/project/Build.scala

@@ -0,0 +1,25 @@
+import sbt._
+import complete.DefaultParsers._
+import Keys._
+
+object B extends Build
+{
+	// This configuration is added to 'sub' only.
+	//  This verifies that delegation works when a configuration is not defined in the project that is being delegated to
+	val newConfig = config("sample")
+
+	val sample = SettingKey[Int]("sample")
+	val check = TaskKey[Unit]("check")
+	
+	lazy val projects = Seq(root, sub)
+	lazy val root = Project("root", file("."), settings = Nil)
+	lazy val sub = Project("sub", file("."), delegates = root :: Nil, configurations = newConfig :: Nil, settings = incSample :: checkTask(4) :: Nil)
+	override lazy val settings =
+		(sample in newConfig := 3) ::
+		checkTask(3) ::
+		Nil
+
+	def incSample = sample <<= sample in newConfig apply (_ + 1)
+	def checkTask(expected: Int) = check <<= sample in newConfig map ( i => assert(i == expected, "Expected " + expected + ", got " + i ) )
+	
+}

sbt/src/sbt-test/project/delegate_config/test

@@ -0,0 +1,11 @@
+-> root/sample
+> sub/sample
+
+-> root/*:sample
+> sub/*:sample
+
+> root/*:check
+> root/check
+
+> sub/*:check
+> sub/check

sbt/src/sbt-test/project/delegates/project/Build.scala

@@ -8,7 +8,7 @@ object B extends Build
 
 	lazy val projects = Seq(root, sub)
 	lazy val root = Project("root", file("."))
-	lazy val sub = Project("sub", file(".")) delegates(root) settings(check <<= checkTask)
+	lazy val sub = Project("sub", file(".")) delegateTo(root) settings(check <<= checkTask)
 
 	lazy val checkTask = InputTask(_ => Space ~> NatBasic) { result =>
 		(result, maxErrors) map { (i, max)  =>