Remember current URI + more tests. Review by @harrah

main/Load.scala

@@ -534,8 +534,10 @@ object Load
 	}
 
 	def initialSession(structure: BuildStructure, rootEval: () => Eval, s: State): SessionSettings = {
-		val current = s get Keys.sessionSettings map (_.currentProject) getOrElse Map.empty
-		new SessionSettings(structure.root, projectMap(structure, current), structure.settings, Map.empty, Nil, rootEval)
+		val session = s get Keys.sessionSettings
+		val currentProject = session map (_.currentProject) getOrElse Map.empty
+		val currentBuild = session map (_.currentBuild) filter (uri => structure.units.keys exists (uri ==)) getOrElse structure.root
+		new SessionSettings(currentBuild, projectMap(structure, currentProject), structure.settings, Map.empty, Nil, rootEval)
 	}
 
 	def initialSession(structure: BuildStructure, rootEval: () => Eval): SessionSettings =
@@ -546,8 +548,8 @@ object Load
 		val units = structure.units
 		val getRoot = getRootProject(units)
 		def project(uri: URI) = {
-			current get uri map {
-				p => if (structure allProjects uri map (_.id) contains p) p else getRoot(uri)
+			current get uri filter {
+				p => structure allProjects uri map (_.id) contains p
 			} getOrElse getRoot(uri)
 		}
 		units.keys.map(uri => (uri, project(uri))).toMap

sbt/src/sbt-test/actions/reload/changes/Build1.scala

@@ -0,0 +1,8 @@
+import sbt._
+
+object Build1 extends Build
+{
+	lazy val root1 = Project("root1", file("root1")) settings(
+		TaskKey[Unit]("g") := {}
+	)
+}

sbt/src/sbt-test/actions/reload/changes/Build2.scala

@@ -0,0 +1,6 @@
+import sbt._
+
+object Build2 extends Build
+{
+	lazy val root2 = Project("root2", file("root2"))
+}

sbt/src/sbt-test/actions/reload/test

@@ -2,4 +2,12 @@
 > project sub
 > f
 > reload
-> f
+> f
+$ copy-file changes/Build1.scala project/TestProject.scala
+> reload
+-> f
+> g
+# The current URI should be kept
+$ copy-file changes/Build2.scala project/First.scala
+> reload
+> g