Fix unused variable in MuDISGenerator

First argument of SetPositions was unused and as a result silently
ignored. As we are already changing it, remove default parameters,
which are probably outdated, and could lead to surprising behaviour.
Code using the old signature should break noticeably, and should be
trivial to fix by removing the first argument.

CHANGELOG.md

@@ -31,6 +31,7 @@ it in future.
 * Cleaned up Veto Implementation
 * Fix crash of event display, PID when no entrance lid present
 * Close ShipReco.py output file
+* Remove unused (silently ignored!) argument for MuDISGenerator::SetPositions
 
 ### Changed
 

macro/run_simScript.py

@@ -403,7 +403,7 @@
  # in front of UVT up to tracking station 1
  mu_start, mu_end = ship_geo.Chamber1.z-ship_geo.chambers.Tub1length-10.*u.cm,ship_geo.TrackStation1.z
  print('MuDIS position info input=',mu_start, mu_end)
- DISgen.SetPositions(ship_geo.target.z0, mu_start, mu_end)
+ DISgen.SetPositions(mu_start, mu_end)
  DISgen.Init(inputFile,options.firstEvent)
  primGen.AddGenerator(DISgen)
  options.nEvents = min(options.nEvents,DISgen.GetNevents())

shipgen/MuDISGenerator.h

@@ -28,9 +28,10 @@ class MuDISGenerator : public FairGenerator
   virtual Bool_t Init(const char*); //!
   Int_t GetNevents();
 
-  void SetPositions(Double_t zTa, Double_t zS=-3400., Double_t zE=2650.){
-    startZ      = zS;
-    endZ        = zE;
+  void SetPositions(Double_t z_start, Double_t z_end)
+  {
+      startZ = z_start;
+      endZ = z_end;
   }
 
  private: