Check if the proper seed is saved in file

ROOT changes the return value of the GetSeed function of TRandom3. FairRoot
uses this function to write the seed value used in the simulation to the
FairBaseParSet parameter container for later usage. With ROOT > 6.24 the
saved value is wrong due to the change in the ROOT code.
Add a test which fails if the used seed value isn't properly stored in the
parameter container.

(cherry picked from commit 812db13)

examples/simulation/Tutorial2/macros/CMakeLists.txt

@@ -12,21 +12,30 @@ GENERATE_ROOT_TEST_SCRIPT(${CMAKE_CURRENT_SOURCE_DIR}/read_digis.C)
 GENERATE_ROOT_TEST_SCRIPT(${CMAKE_CURRENT_SOURCE_DIR}/run_background.C)
 GENERATE_ROOT_TEST_SCRIPT(${CMAKE_CURRENT_SOURCE_DIR}/run_signal.C)
 GENERATE_ROOT_TEST_SCRIPT(${CMAKE_CURRENT_SOURCE_DIR}/run_tutorial2.C)
+GENERATE_ROOT_TEST_SCRIPT(${CMAKE_CURRENT_SOURCE_DIR}/compare_seed_value.C)
 
 set(maxTestTime 60)
 
 add_test(NAME ex_sim_tutorial2
-         COMMAND ${CMAKE_CURRENT_BINARY_DIR}/run_tutorial2.sh)
+         COMMAND ${CMAKE_CURRENT_BINARY_DIR}/run_tutorial2.sh  10 \"TGeant4\" true 333)
 set_tests_properties(ex_sim_tutorial2 PROPERTIES
   TIMEOUT ${maxTestTime}
   PASS_REGULAR_EXPRESSION "Macro finished successfully"
   FIXTURES_SETUP fixtures.ex_sim_tutorial2_sim
 )
 
+add_test(NAME ex_compare_seed_value
+         COMMAND ${CMAKE_CURRENT_BINARY_DIR}/compare_seed_value.sh \"tutorial2_pions.params_p2.000_t0_n10.root\" 333)
+set_tests_properties(ex_compare_seed_value PROPERTIES
+  TIMEOUT ${maxTestTime}
+  FIXTURES_REQUIRED fixtures.ex_sim_tutorial2_sim
+  FIXTURES_SETUP fixtures.ex_compare_seed_value
+)
+
 add_test(NAME ex_sim_tutorial2_create_digis
          COMMAND ${CMAKE_CURRENT_BINARY_DIR}/create_digis.sh)
 set_tests_properties(ex_sim_tutorial2_create_digis PROPERTIES
-  FIXTURES_REQUIRED fixtures.ex_sim_tutorial2_sim
+  FIXTURES_REQUIRED fixtures.ex_compare_seed_value
   TIMEOUT ${maxTestTime}
   PASS_REGULAR_EXPRESSION "Macro finished successfully"
   FIXTURES_SETUP fixtures.ex_sim_tutorial2_digi

examples/simulation/Tutorial2/macros/compare_seed_value.C

@@ -0,0 +1,20 @@
+int compare_seed_value(TString filename, UInt_t initial_seed) {
+
+  // Open parameter file and get the stored random seed from the
+  // FairBaseParSet parameter container
+  // Compare the random seed with the expected one set during the
+  // transport run
+
+  std::unique_ptr<TFile> myFile( TFile::Open(filename) );
+  std::unique_ptr<FairBaseParSet> par(myFile->Get<FairBaseParSet>("FairBaseParSet"));
+  UInt_t seed = par->GetRndSeed();
+
+  if ( seed == initial_seed ) {
+    return 0;
+  }
+  else {
+    std::cout << "Expected seed value  : " << initial_seed << std::endl;
+    std::cout << "Seed value from file : " << seed << std::endl;
+    return 1;
+  }
+}

examples/simulation/Tutorial2/macros/run_tutorial2.C

@@ -12,7 +12,8 @@
 #include <TSystem.h>
 #include <memory>
 
-void run_tutorial2(Int_t nEvents = 10, TString mcEngine = "TGeant4", Bool_t isMT = true)
+void run_tutorial2(Int_t nEvents = 10, TString mcEngine = "TGeant4",
+                   Bool_t isMT = true, UInt_t initial_seed=98989)
 {
     TString dir = getenv("VMCWORKDIR");
 
@@ -49,7 +50,7 @@ void run_tutorial2(Int_t nEvents = 10, TString mcEngine = "TGeant4", Bool_t isMT
                            nEvents);
 
     // Set the random seed
-    gRandom->SetSeed(98989);
+    gRandom->SetSeed(initial_seed);
 
     // In general, the following parts need not be touched
     // ========================================================================