Avoid throwing an exception when sorting identical paths

os/src/Path.scala

@@ -408,15 +408,21 @@ object Path {
       else{
         var xSeg = ""
         var ySeg = ""
-        var i = -1
+        var i = 0
+        var result: Integer = null
         while ({
-          i += 1
           xSeg = x.getSegment(i)
           ySeg = y.getSegment(i)
-          i < xSegCount && xSeg == ySeg
+          i += 1
+          val compared = Ordering.String.compare(xSeg, ySeg)
+          if (i < xSegCount && compared == 0) true // continue
+          else {
+            result = compared
+            false
+          }
         }) ()
-        if (i == xSegCount) 0
-        else Ordering.String.compare(xSeg, ySeg)
+
+        result
       }
     }
   }

os/test/src/PathTests.scala

@@ -327,10 +327,21 @@ object PathTests extends TestSuite{
       }
     }
     test("sorting"){
-      assert(
-        Seq(root/"c", root, root/"b", root/"a").sorted == Seq(root, root/"a", root/"b", root/"c"),
+      test - {
+        assert(
+          Seq(root/"c", root, root/"b", root/"a").sorted ==
+          Seq(root, root/"a", root/"b", root/"c")
+        )
+      }
+
+      test - assert(
         Seq(up/"c", up/up/"c", rel/"b"/"c", rel/"a"/"c", rel/"a"/"d").sorted ==
-          Seq(rel/"a"/"c", rel/"a"/"d", rel/"b"/"c", up/"c", up/up/"c")
+        Seq(rel/"a"/"c", rel/"a"/"d", rel/"b"/"c", up/"c", up/up/"c")
+      )
+
+      test - assert(
+        Seq(os.root / "yo", os.root / "yo").sorted ==
+        Seq(os.root / "yo", os.root / "yo")
       )
     }
     test("construction"){