Merge pull request #1488 from sbt/wip/fix-1375

Fixes #1375 - Check for empty filenames.

main/src/main/scala/sbt/Project.scala

@@ -242,7 +242,10 @@ object Project extends ProjectExtra {
   def normalizeProjectID(id: String): Either[String, String] =
     {
       val attempt = normalizeBase(id)
-      val refined = if (!validProjectIDStart(attempt.substring(0, 1))) "root-" + attempt else attempt
+      val refined =
+        if (attempt.length < 1) "root"
+        else if (!validProjectIDStart(attempt.substring(0, 1))) "root-" + attempt
+        else attempt
       validProjectID(refined).toLeft(refined)
     }
   private[this] def normalizeBase(s: String) = s.toLowerCase(Locale.ENGLISH).replaceAll("""\W+""", "-")

main/src/test/scala/ProjectSpec.scala

@@ -0,0 +1,18 @@
+package sbt
+
+import org.specs2.Specification
+
+class ProjectSpec extends Specification {
+  def is = s2"""
+
+  This is a specification to check utility methods on the Project object
+
+  Project should
+    normalize projectIDs if they are empty  ${normalizeEmptyFileName}
+
+  """
+
+  def emptyFilename = ""
+
+  def normalizeEmptyFileName = Project.normalizeProjectID(emptyFilename) must equalTo(Right("root"))
+}

notes/0.13.6.md

@@ -35,6 +35,7 @@
   [1477]: https://github.com/sbt/sbt/pull/1477
   [1486]: https://github.com/sbt/sbt/pull/1486
   [1487]: https://github.com/sbt/sbt/pull/1487
+  [1488]: https://github.com/sbt/sbt/pull/1488
   [@dansanduleac]: https://github.com/dansanduleac
   [@2m]: https://github.com/2m
   [@pvlugter]: https://github.com/pvlugter
@@ -80,6 +81,7 @@
 - Works around "Not a simple type" breaking `-Xfatal-warnings`. [#1477][1477] by [@puffnfresh][@puffnfresh]
 - Fixes sLog usage in tandem with the `set` comamnd [#1486][1486] [@jsuereth][@jsuereth]
 - Test suites with whitespace will have prettier filenames [#1487][1487] [@jsuereth][@jsuereth]
+- sbt no longer crashes when run in root directory [#1488][1488] by [@jsuereth][@jsuereth]
 
 ### enablePlugins/disablePlugins