Fixing code style and updating if logic on when to check for zero values

mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala

@@ -736,11 +736,9 @@ class SparseVector(
       }
 
       // look for inactive values in case all active node values are negative
-      if(size != values.size && maxValue <= 0){
+      if (size != values.size && maxValue <= 0){
         val firstInactiveIdx = calcFirstInactiveIdx(0)
-        if(maxValue == 0){
-          if(firstInactiveIdx >= maxIdx) maxIdx else maxIdx = firstInactiveIdx
-        }else{
+        if (!(maxValue == 0 && firstInactiveIdx >= maxIdx)){
           maxIdx = firstInactiveIdx
         }
         maxValue = 0

mllib/src/test/scala/org/apache/spark/mllib/linalg/VectorsSuite.scala

@@ -91,22 +91,26 @@ class VectorsSuite extends FunSuite {
     val max = vec2.argmax
     assert(max === 3)
 
-    val vec3 = Vectors.sparse(5,Array(2, 4),Array(1.0,-.7))
+    val vec3 = Vectors.sparse(5,Array(2, 3, 4),Array(1.0, 0.0, -.7))
     val max2 = vec3.argmax
     assert(max2 === 2)
 
     // check for case that sparse vector is created with only negative values {0.0, 0.0,-1.0, -0.7, 0.0}
-    val vec4 = Vectors.sparse(5,Array(2, 3),Array(-1.0,-.7))
+    val vec4 = Vectors.sparse(5,Array(2, 3),Array(-1.0, -.7))
     val max3 = vec4.argmax
     assert(max3 === 0)
 
-    val vec5 = Vectors.sparse(11,Array(0, 3, 10),Array(-1.0,-.7,0.0))
+    val vec5 = Vectors.sparse(11,Array(0, 3, 10),Array(-1.0, -.7, 0.0))
     val max4 = vec5.argmax
     assert(max4 === 1)
 
-    val vec6 = Vectors.sparse(5,Array(0, 1, 3),Array(-1.0, 0.0, -.7))
+    val vec6 = Vectors.sparse(11,Array(0, 1, 2),Array(-1.0, -.7, 0.0))
     val max5 = vec6.argmax
-    assert(max5 === 1)
+    assert(max5 === 2)
+
+    val vec7 = Vectors.sparse(5,Array(0, 1, 3),Array(-1.0, 0.0, -.7))
+    val max6 = vec7.argmax
+    assert(max6 === 1)
 
     var vec8 = Vectors.sparse(5,Array(1, 2),Array(0.0, -1.0))
     val max7 = vec8.argmax