Track public inherited dependencies.

There is a public inherited dependency on each (normalized) base
class of a public template (class, module, trait, structural type).

compile/interface/src/main/scala/xsbt/API.scala

@@ -39,6 +39,7 @@ final class API(val global: CallbackGlobal) extends Compat
 		def processScalaUnit(unit: CompilationUnit)
 		{
 			val sourceFile = unit.source.file.file
+			currentSourceFile = sourceFile
 			debug("Traversing " + sourceFile)
 			val traverser = new TopLevelHandler(sourceFile)
 			traverser.apply(unit.body)
@@ -50,6 +51,10 @@ final class API(val global: CallbackGlobal) extends Compat
 		}
 	}
 
+	// Tracks the source file associated with the CompilationUnit currently being processed by the API phase.
+	// This is used when recording inheritance dependencies.
+	private[this] var currentSourceFile: File = _
+
 	// this cache reduces duplicate work both here and when persisting
 	//   caches on other structures had minimal effect on time and cache size
 	//   (tried: Definition, Modifier, Path, Id, String)
@@ -237,8 +242,18 @@ final class API(val global: CallbackGlobal) extends Compat
 		mkStructure(s, baseTypes, ds, is)
 	}
 
-	private def mkStructure(s: Symbol, bases: List[Type], declared: List[Symbol], inherited: List[Symbol]): xsbti.api.Structure =
+	// If true, this template is publicly visible and should be processed as a public inheritance dependency.
+	// Local classes and local refinements will never be traversed by the api phase, so we don't need to check for that.
+	private[this] def isPublicStructure(s: Symbol): Boolean =
+		s.isStructuralRefinement || 
+			// do not consider templates that are private[this] or private
+			!(s.isPrivate && (s.privateWithin == NoSymbol || s.isLocal))
+
+	private def mkStructure(s: Symbol, bases: List[Type], declared: List[Symbol], inherited: List[Symbol]): xsbti.api.Structure = {
+		if(isPublicStructure(s))
+			addInheritedDependencies(currentSourceFile, bases.map(_.dealias.typeSymbol))
 		new xsbti.api.Structure(lzy(types(s, bases)), lzy(processDefinitions(s, declared)), lzy(processDefinitions(s, inherited)))
+	}
 	private def processDefinitions(in: Symbol, defs: List[Symbol]): Array[xsbti.api.Definition] =
 		sort(defs.toArray).flatMap( (d: Symbol) => definition(in, d))
 	private[this] def sort(defs: Array[Symbol]): Array[Symbol] = {

compile/interface/src/main/scala/xsbt/Analyzer.scala

@@ -33,9 +33,11 @@ final class Analyzer(val global: CallbackGlobal) extends Compat
 				// build dependencies structure
 				val sourceFile = unit.source.file.file
 				callback.beginSource(sourceFile)
-				for(on <- unit.depends)
+				for(on <- unit.depends) processDependency(on, inherited=false)
+				for(on <- inheritedDependencies.getOrElse(sourceFile, Nil: Iterable[Symbol])) processDependency(on, inherited=true)
+				def processDependency(on: Symbol, inherited: Boolean)
 				{
-					def binaryDependency(file: File, className: String) = callback.binaryDependency(file, className, sourceFile)
+					def binaryDependency(file: File, className: String) = callback.binaryDependency(file, className, sourceFile /*, inherited*/)
 					val onSource = on.sourceFile
 					if(onSource == null)
 					{
@@ -53,7 +55,7 @@ final class Analyzer(val global: CallbackGlobal) extends Compat
 						}
 					}
 					else
-						callback.sourceDependency(onSource.file, sourceFile)
+						callback.sourceDependency(onSource.file, sourceFile /*, inherited*/)
 				}
 
 				// build list of generated classes

compile/interface/src/main/scala/xsbt/CompilerInterface.scala

@@ -42,6 +42,11 @@ sealed abstract class CallbackGlobal(settings: Settings, reporter: reporters.Rep
 			case multi: MultipleOutput => multi.outputGroups.toStream map (_.outputDirectory)
 		}
 	}
+	// Map source files to public inherited dependencies.  These dependencies are tracked as the symbol for the dealiased base class.
+	val inheritedDependencies = new mutable.HashMap[File, mutable.Set[Symbol]]
+	def addInheritedDependencies(file: File, deps: Iterable[Symbol]) {
+		inheritedDependencies.getOrElseUpdate(file, new mutable.HashSet) ++= deps
+	}
 }
 class InterfaceCompileFailed(val arguments: Array[String], val problems: Array[Problem], override val toString: String) extends xsbti.CompileFailed