2 files changed, 47 insertions, 0 deletions
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala b/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala
index 541f3288b6..52d6468a72 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/util/MLUtils.scala
@@ -82,6 +82,18 @@ object MLUtils {
           val value = indexAndValue(1).toDouble
           (index, value)
         }.unzip
+
+        // check if indices are one-based and in ascending order
+        var previous = -1
+        var i = 0
+        val indicesLength = indices.length
+        while (i < indicesLength) {
+          val current = indices(i)
+          require(current > previous, "indices should be one-based and in ascending order" )
+          previous = current
+          i += 1
+        }
+
         (label, indices.toArray, values.toArray)
       }
 
diff --git a/mllib/src/test/scala/org/apache/spark/mllib/util/MLUtilsSuite.scala b/mllib/src/test/scala/org/apache/spark/mllib/util/MLUtilsSuite.scala
index 734b7babec..70219e9ad9 100644
--- a/mllib/src/test/scala/org/apache/spark/mllib/util/MLUtilsSuite.scala
+++ b/mllib/src/test/scala/org/apache/spark/mllib/util/MLUtilsSuite.scala
@@ -25,6 +25,7 @@ import breeze.linalg.{squaredDistance => breezeSquaredDistance}
 import com.google.common.base.Charsets
 import com.google.common.io.Files
 
+import org.apache.spark.SparkException
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.mllib.linalg.{DenseVector, SparseVector, Vectors}
 import org.apache.spark.mllib.regression.LabeledPoint
@@ -108,6 +109,40 @@ class MLUtilsSuite extends SparkFunSuite with MLlibTestSparkContext {
     Utils.deleteRecursively(tempDir)
   }
 
+  test("loadLibSVMFile throws IllegalArgumentException when indices is zero-based") {
+    val lines =
+      """
+        |0
+        |0 0:4.0 4:5.0 6:6.0
+      """.stripMargin
+    val tempDir = Utils.createTempDir()
+    val file = new File(tempDir.getPath, "part-00000")
+    Files.write(lines, file, Charsets.US_ASCII)
+    val path = tempDir.toURI.toString
+
+    intercept[SparkException] {
+      loadLibSVMFile(sc, path).collect()
+    }
+    Utils.deleteRecursively(tempDir)
+  }
+
+  test("loadLibSVMFile throws IllegalArgumentException when indices is not in ascending order") {
+    val lines =
+      """
+        |0
+        |0 3:4.0 2:5.0 6:6.0
+      """.stripMargin
+    val tempDir = Utils.createTempDir()
+    val file = new File(tempDir.getPath, "part-00000")
+    Files.write(lines, file, Charsets.US_ASCII)
+    val path = tempDir.toURI.toString
+
+    intercept[SparkException] {
+      loadLibSVMFile(sc, path).collect()
+    }
+    Utils.deleteRecursively(tempDir)
+  }
+
   test("saveAsLibSVMFile") {
     val examples = sc.parallelize(Seq(
       LabeledPoint(1.1, Vectors.sparse(3, Seq((0, 1.23), (2, 4.56)))),