SystemML diag behavior issue

diag_behavior.scala

/*
In this example I create two matrices in the same manner, extract the diagonal, and then turn the nx1 
matrix of the diagonal values into a diagonal matrix by calling `diag` again. When the initial matrix contains all 1s, 
it works as expected. However, when the initial matrix contains all zeros, the second `diag` does not convert the nx1 
matrix of diagonal values to a diagonal matrix. I can work around this behavior, but I thought I should bring it to your attention.
*/

val systemml_alg = 
"""
fileOut1 = ""
fileOut2 = ""

test_fun = function(double x) return(matrix[double] out) {
  X = matrix(x, 10, 10)
  out = diag(diag(X));
}

Out1 = test_fun(0)
Out2 = test_fun(1)

write(Out1, fileOut1)
write(Out2, fileOut2)
"""

import org.apache.sysml.api.MLContext

val ml = new MLContext(sc)
ml.setConfig("scratch", "/mnt/work/scratch")

ml.registerOutput("Out1")
ml.registerOutput("Out2")

val outputs = ml.executeScript(systemml_alg)
val Out1 = outputs.getDF(sqlContext, "Out1")
val Out2 = outputs.getDF(sqlContext, "Out2")

// OUTPUT:
// Out1: org.apache.spark.sql.DataFrame = [ID: double, C1: double]
// Out2: org.apache.spark.sql.DataFrame = [ID: double, C1: double, C2: double, C3: double, C4: double, C5: double, C6: double, C7: double, C8: double, C9: double, C10: double]