Merge branch 'hepmc3_20.10.21_QGSJET' into 'master'

Fix the crashes in QGSJET

See merge request atlas/athena!47420

Generators/QGSJet_i/src/QGSJet.cxx

@@ -53,6 +53,32 @@ extern "C"
     // cross section info 
   void crmc_xsection_f_(double &xsigtot, double &xsigine, double &xsigela, double &xsigdd, 
       double &xsigsd, double &xsloela, double &xsigtotaa, double &xsigineaa, double &xsigelaaa);
+
+#ifdef HEPMC3
+extern struct eposhepevt
+{
+    int        nevhep;
+    int        nhep;
+    int        isthep[HEPEVT_EntriesAllocation];
+    int        idhep [HEPEVT_EntriesAllocation];
+    int        jmohep[HEPEVT_EntriesAllocation][2];
+    int        jdahep[HEPEVT_EntriesAllocation][2];
+    double     phep  [HEPEVT_EntriesAllocation][5];
+    double     vhep  [HEPEVT_EntriesAllocation][4];
+} hepevt_;                              
+struct hepmc3hepevt
+{
+    int        nevhep;
+    int        nhep;
+    int        isthep[10000];
+    int        idhep [10000];
+    int        jmohep[10000][2];
+    int        jdahep[10000][2];
+    double     phep  [10000][5];
+    double     vhep  [10000][4];
+} localhepevt_;  
+#endif
+
 } 
 extern "C"
 {
@@ -231,8 +257,8 @@ StatusCode QGSJet::genInitialize()
 
     // setup HepMC
 #ifdef HEPMC3
-   /* This ifdef   is used for consistency */
-   /* HepMC3 Does not need a setup here */
+    /// Inlined
+    HepMC::HEPEVT_Wrapper::set_hepevt_address((char*)(&localhepevt_));
 #else
     HepMC::HEPEVT_Wrapper::set_sizeof_int(sizeof( int ));
     HepMC::HEPEVT_Wrapper::set_sizeof_real( 8 );
@@ -312,6 +338,30 @@ StatusCode QGSJet::fillEvt( HepMC::GenEvent* evt )
 
   HepMC::HEPEVT_Wrapper::set_event_number(m_events);
 #ifdef HEPMC3
+  ///If HepMC3 has been compiled with different block size than is used in the interface,
+  /// only the inlined functions can be used without restrictions.
+  /// The convert functions are compiled and should operate on the block of matching size.
+  /// The best solution would be to define a single block sze for all Athena.
+  localhepevt_.nevhep = m_events;
+  localhepevt_.nhep = std::min(10000, hepevt_.nhep);
+   for (int i = 0; i < localhepevt_.nhep; i++ ) {
+    localhepevt_.isthep[i] = hepevt_.isthep[i];
+    localhepevt_.idhep [i] = hepevt_.idhep [i];
+    for (int k = 0; k < 2; k++) localhepevt_.jmohep[i][k] = hepevt_.jmohep[i][k];
+    for (int k = 0; k < 2; k++) localhepevt_.jdahep[i][k] = hepevt_.jdahep[i][k];
+    for (int k = 0; k < 5; k++) localhepevt_.phep  [i][k] = hepevt_.phep  [i][k];
+    for (int k = 0; k < 4; k++) localhepevt_.vhep  [i][k] = hepevt_.vhep  [i][k];
+    localhepevt_.jmohep[i][1] = std::max(localhepevt_.jmohep[i][0],localhepevt_.jmohep[i][1]);
+    localhepevt_.jdahep[i][1] = std::max(localhepevt_.jdahep[i][0],localhepevt_.jdahep[i][1]);
+    /// For some interesting reason EPOS marks beam particle parents as -1 -1
+    if (localhepevt_.jmohep[i][0] <= 0 && localhepevt_.jmohep[i][1] <= 0 ) 
+    {
+      localhepevt_.jmohep[i][0] = 0;
+      localhepevt_.jmohep[i][1] = 0;
+      localhepevt_.isthep[i] = 4;
+    }
+   } 
+  /// Compiled!
   HepMC::HEPEVT_Wrapper::HEPEVT_to_GenEvent(evt);
 #else 
   HepMC::IO_HEPEVT hepio;