Fixes #582. Don't merge dependencies with mismatched transitive/force/changing values.

This avoids the assertion, but note that Ivy is unlikely to work properly in this situation.

ivy/Ivy.scala

@@ -474,18 +474,23 @@ private object IvySbt
 	*/
 	def mergeDuplicateDefinitions(dependencies: Seq[DependencyDescriptor]): Seq[DependencyDescriptor] =
 	{
-		val deps = new java.util.LinkedHashMap[ModuleRevisionId, DependencyDescriptor]
+		// need to preserve basic order of dependencies: can't use dependencies.groupBy 
+		val deps = new java.util.LinkedHashMap[ModuleRevisionId, List[DependencyDescriptor]]
 		for( dd <- dependencies )
 		{
 			val id = dd.getDependencyRevisionId
 			val updated = deps get id match {
-				case null => dd
-				case v => ivyint.MergeDescriptors(v, dd)
+				case null => dd :: Nil
+				case v => dd :: v
 			}
 			deps.put(id, updated)
 		}
+
 			import collection.JavaConverters._
-		deps.values.asScala.toSeq
+		deps.values.asScala.toSeq.flatMap { dds =>
+			val mergeable = (dds, dds.tail).zipped.forall( ivyint.MergeDescriptors.mergeable _)
+			if(mergeable) dds.reverse.reduceLeft(ivyint.MergeDescriptors.apply _) :: Nil else dds
+		}
 	}
 
 	/** Transforms an sbt ModuleID into an Ivy DefaultDependencyDescriptor.*/

ivy/MergeDescriptors.scala

@@ -15,20 +15,24 @@ import util.extendable.ExtendableItem
 
 private[sbt] object MergeDescriptors
 {
+	def mergeable(a: DependencyDescriptor, b: DependencyDescriptor): Boolean =
+		a.isForce == b.isForce &&
+		a.isChanging == b.isChanging &&
+		a.isTransitive == b.isTransitive &&
+		a.getParentRevisionId == b.getParentRevisionId &&
+		a.getNamespace == b.getNamespace && {
+			val amrid = a.getDependencyRevisionId
+			val bmrid = b.getDependencyRevisionId
+			amrid == bmrid
+		} && {
+			val adyn = a.getDynamicConstraintDependencyRevisionId
+			val bdyn = b.getDynamicConstraintDependencyRevisionId
+			adyn == bdyn
+		}
+
 	def apply(a: DependencyDescriptor, b: DependencyDescriptor): DependencyDescriptor =
 	{
-		assert(a.isForce == b.isForce)
-		assert(a.isChanging == b.isChanging)
-		assert(a.isTransitive == b.isTransitive)
-		assert(a.getParentRevisionId == b.getParentRevisionId)
-		val amrid = a.getDependencyRevisionId
-		val bmrid = b.getDependencyRevisionId
-		assert(amrid == bmrid)
-		val adyn = a.getDynamicConstraintDependencyRevisionId
-		val bdyn = b.getDynamicConstraintDependencyRevisionId
-		assert(adyn == bdyn)
-		assert(a.getNamespace == b.getNamespace)
-
+		assert(mergeable(a,b))
 		new MergedDescriptors(a,b)
 	}
 }

sbt/src/sbt-test/dependency-management/multiple-classifiers/changes/non-mergeable.sbt

@@ -0,0 +1,13 @@
+libraryDependencies ++= Seq(
+	"org.easytesting" % "fest-assert"  % "1.4",
+	"org.easytesting" % "fest-assert"  % "1.4" % "test" intransitive())
+
+autoScalaLibrary := false
+
+TaskKey[Unit]("check") <<= (externalDependencyClasspath in Compile, externalDependencyClasspath in Test) map { (cp, tcp) =>
+        assert(cp.size == 2, "Expected 2 jars on compile classpath, got: " + cp.files.mkString("(", ", ", ")"))
+	// this should really be 1 because of intransitive(), but Ivy doesn't handle this.
+	// So, this test can only check that the assertion reported in #582 isn't triggered.
+        assert(tcp.size == 2, "Expected 2 jar on test classpath, got: " + tcp.files.mkString("(", ", ", ")"))
+}
+

sbt/src/sbt-test/dependency-management/multiple-classifiers/test

@@ -1,3 +1,9 @@
 > check
 
 > check-pom
+
+$ delete build.sbt
+$ copy-file changes/non-mergeable.sbt build.sbt
+
+> reload
+> check