Fixing NullPointerError caused by reading String from Ivy directly

ivy/src/main/scala/sbt/IvyRetrieve.scala

@@ -71,13 +71,13 @@ object IvyRetrieve {
     }
     val revId = dep.getResolvedId
     val moduleId = toModuleID(revId)
-    val branch = Some(revId.getBranch)
+    val branch = Option(revId.getBranch)
     val (status, publicationDate, resolver, artifactResolver) = dep.isLoaded match {
       case true =>
-        (Some(dep.getDescriptor.getStatus),
+        (Option(dep.getDescriptor.getStatus),
           Some(new ju.Date(dep.getPublication)),
-          Some(dep.getModuleRevision.getResolver.getName),
-          Some(dep.getModuleRevision.getArtifactResolver.getName))
+          Option(dep.getModuleRevision.getResolver.getName),
+          Option(dep.getModuleRevision.getArtifactResolver.getName))
       case _ => (None, None, None, None)
     }
     val (evicted, evictedData, evictedReason) = dep.isEvicted(confReport.getConfiguration) match {
@@ -89,7 +89,7 @@ object IvyRetrieve {
       case _ => (false, None, None)
     }
     val problem = dep.hasProblem match {
-      case true => Some(dep.getProblem.getMessage)
+      case true => Option(dep.getProblem.getMessage)
       case _    => None
     }
     val mdOpt = for {

ivy/src/main/scala/sbt/UpdateReport.scala

@@ -48,10 +48,12 @@ final class ConfigurationReport(
     val modules: Seq[ModuleReport],
     val details: Seq[ModuleDetailReport],
     val evicted: Seq[ModuleID]) {
-  // def this(configuration: String, modules: Seq[ModuleReport], evicted: Seq[ModuleID]) =
-  //  this(configuration, modules, Nil, evicted)
+  def this(configuration: String, modules: Seq[ModuleReport], evicted: Seq[ModuleID]) =
+    this(configuration, modules, Nil, evicted)
 
-  override def toString = "\t" + configuration + ":\n" + modules.mkString + evicted.map("\t\t(EVICTED) " + _ + "\n").mkString
+  override def toString = s"\t$configuration:\n" +
+    (if (details.isEmpty) modules.mkString + evicted.map("\t\t(EVICTED) " + _ + "\n").mkString
+    else details.mkString)
 
   /**
    * All resolved modules for this configuration.
@@ -73,8 +75,10 @@ final class ModuleDetailReport(
     val organization: String,
     val name: String,
     val modules: Seq[ModuleReport]) {
-  override def toString: String =
-    { s"$organization:$name" }
+  override def toString: String = {
+    val details = modules map { _.detailReport }
+    s"\t$organization:$name\n${details.mkString}\n"
+  }
 }
 
 /**
@@ -104,11 +108,40 @@ final class ModuleReport(
     val licenses: Seq[(String, URL)],
     val callers: Seq[Caller]) {
 
-  override def toString = {
-    val arts = artifacts.map(_.toString) ++ missingArtifacts.map(art => "(MISSING) " + art)
+  private[this] lazy val arts: Seq[String] = artifacts.map(_.toString) ++ missingArtifacts.map(art => "(MISSING) " + art)
+  override def toString: String = {
     s"\t\t$module: " +
       (if (arts.size <= 1) "" else "\n\t\t\t") + arts.mkString("\n\t\t\t") + "\n"
   }
+  private[sbt] def detailReport: String =
+    s"\t\t- ${module.revision}\n" +
+      (if (arts.size <= 1) "" else arts.mkString("\t\t\t", "\n\t\t\t", "\n")) +
+      reportStr("status", status) +
+      reportStr("publicationDate", publicationDate map { _.toString }) +
+      reportStr("resolver", resolver) +
+      reportStr("artifactResolver", artifactResolver) +
+      reportStr("evicted", Some(evicted.toString)) +
+      reportStr("evictedData", evictedData) +
+      reportStr("evictedReason", evictedReason) +
+      reportStr("problem", problem) +
+      reportStr("homepage", homepage) +
+      reportStr("textraAttributes",
+        if (extraAttributes.isEmpty) None
+        else { Some(extraAttributes.toString) }) +
+        reportStr("isDefault", isDefault map { _.toString }) +
+        reportStr("branch", branch) +
+        reportStr("configurations",
+          if (configurations.isEmpty) None
+          else { Some(configurations.mkString(", ")) }) +
+          reportStr("licenses",
+            if (licenses.isEmpty) None
+            else { Some(licenses.mkString(", ")) }) +
+            reportStr("callers",
+              if (callers.isEmpty) None
+              else { Some(callers.mkString(", ")) })
+  private[sbt] def reportStr(key: String, value: Option[String]): String =
+    value map { x => s"\t\t\t$key: $x\n" } getOrElse ""
+
   def retrieve(f: (ModuleID, Artifact, File) => File): ModuleReport =
     copy(artifacts = artifacts.map { case (art, file) => (art, f(module, art, file)) })
 

main/src/main/scala/sbt/Defaults.scala

@@ -1269,13 +1269,11 @@ object Classpaths {
         }
       def doWork: In => UpdateReport =
         Tracked.inputChanged(cacheFile / "inputs") { (inChanged: Boolean, in: In) =>
-          // TODO FIX THIS!
-          // val outCache = Tracked.lastOutput[In, UpdateReport](outCacheFile) {
-          //   case (_, Some(out)) if uptodate(inChanged, out) => out
-          //   case _ => work(in)
-          // }
-          // outCache(in)
-          work(in)
+          val outCache = Tracked.lastOutput[In, UpdateReport](outCacheFile) {
+            case (_, Some(out)) if uptodate(inChanged, out) => out
+            case _ => work(in)
+          }
+          outCache(in)
         }
       val f = if (skip && !force) skipWork else doWork
       f(module.owner.configuration :+: module.moduleSettings :+: config :+: HNil)