Graph Builder: Interferogram OP, external dem reset


There is a problem with Graph Bulder loading Interferogram Op external dem from xml.
Steps to reproduce:

  1. Clear graph
  2. Add Interferogram Operator
  3. Select “Substract topographic phase”
  4. Select External DEM option, specify the path to file
  5. Save graph
  6. Clear graph/Open another graph builder window
  7. Load saved graph
  8. Check DEM selected: source is reset to “ACE2_5Min (Auto Download)”

SNAP v7, v8 (updated, ubuntu 16). SNAP v8 (updated, windows 7).