From 4872c3f658b9e891a345d0825a2af0e4503f84cc Mon Sep 17 00:00:00 2001
From: Josh Bendavid <Josh.Bendavid@cern.ch>
Date: Mon, 17 Nov 2014 20:54:33 +0100
Subject: [PATCH] Update printout and make pythia8 interface explicitly fail
 when pythia initialization fails (instead of just silently filtering out the
 empty events)

---
 .../Core/interface/HadronizerFilter.h         |  2 +-
 .../plugins/Pythia8Hadronizer.cc              | 23 +++++++++++--------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/GeneratorInterface/Core/interface/HadronizerFilter.h b/GeneratorInterface/Core/interface/HadronizerFilter.h
index 0af02bc0856a8..504c5050a940a 100644
--- a/GeneratorInterface/Core/interface/HadronizerFilter.h
+++ b/GeneratorInterface/Core/interface/HadronizerFilter.h
@@ -369,7 +369,7 @@ namespace edm
       throw edm::Exception(errors::Configuration) 
 	<< "Failed to initialize hadronizer "
 	<< hadronizer_.classname()
-	<< " for internal parton generation\n";
+	<< " for external parton generation\n";
   }
 
   template <class HAD, class DEC>
diff --git a/GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc b/GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc
index 144027ec0ed6c..6fc8d76b33088 100644
--- a/GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc
+++ b/GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc
@@ -304,13 +304,16 @@ Pythia8Hadronizer::~Pythia8Hadronizer()
 
 bool Pythia8Hadronizer::initializeForInternalPartons()
 {
+  
+  bool status = true;
+  
   if ( fInitialState == PP ) // default
   {
     //fMasterGen->init(2212, 2212, comEnergy);
     fMasterGen->settings.mode("Beams:idA", 2212);
     fMasterGen->settings.mode("Beams:idB", 2212);
     fMasterGen->settings.parm("Beams:eCM", comEnergy);
-    fMasterGen->init();
+    status &= fMasterGen->init();
   }
   else if ( fInitialState == PPbar )
   {
@@ -318,7 +321,7 @@ bool Pythia8Hadronizer::initializeForInternalPartons()
     fMasterGen->settings.mode("Beams:idA", 2212);
     fMasterGen->settings.mode("Beams:idB", -2212);
     fMasterGen->settings.parm("Beams:eCM", comEnergy);
-    fMasterGen->init();
+    status &= fMasterGen->init();
   }
   else if ( fInitialState == ElectronPositron )
   {
@@ -326,7 +329,7 @@ bool Pythia8Hadronizer::initializeForInternalPartons()
     fMasterGen->settings.mode("Beams:idA", 11);
     fMasterGen->settings.mode("Beams:idB", -11);
     fMasterGen->settings.parm("Beams:eCM", comEnergy);
-    fMasterGen->init();
+    status &= fMasterGen->init();
   }    
   else 
   {
@@ -350,9 +353,9 @@ bool Pythia8Hadronizer::initializeForInternalPartons()
   //fDecayer->readString("ProcessLevel::resonanceDecays=on");
   fDecayer->settings.flag("ProcessLevel:all", false ); // trick
   fDecayer->settings.flag("ProcessLevel:resonanceDecays", true );
-  fDecayer->init();
+  status &= fDecayer->init();
 
-  return true;
+  return status;
 }
 
 
@@ -361,6 +364,8 @@ bool Pythia8Hadronizer::initializeForExternalPartons()
 
   edm::LogInfo("Pythia8Interface") << "Initializing for external partons";
 
+  bool status = true;
+  
   if((fMasterGen->settings.mode("POWHEG:veto") > 0 || fMasterGen->settings.mode("POWHEG:MPIveto") > 0) && !fEmissionVetoHook) {
 
     if(fJetMatchingHook || fEmissionVetoHook1)
@@ -411,7 +416,7 @@ bool Pythia8Hadronizer::initializeForExternalPartons()
     //fMasterGen->init(LHEInputFileName);
     fMasterGen->settings.mode("Beams:frameType", 4);
     fMasterGen->settings.word("Beams:LHEF", LHEInputFileName);
-    fMasterGen->init();
+    status &= fMasterGen->init();
 
   } else {
 
@@ -426,7 +431,7 @@ bool Pythia8Hadronizer::initializeForExternalPartons()
     //fMasterGen->init(lhaUP.get());
     fMasterGen->settings.mode("Beams:frameType", 5);
     fMasterGen->setLHAupPtr(lhaUP.get());
-    fMasterGen->init();
+    status &= fMasterGen->init();
   }
   
   if ( pythiaPylistVerbosity > 10 )
@@ -442,9 +447,9 @@ bool Pythia8Hadronizer::initializeForExternalPartons()
   //fDecayer->readString("ProcessLevel::resonanceDecays=on");
   fDecayer->settings.flag("ProcessLevel:all", false ); // trick
   fDecayer->settings.flag("ProcessLevel:resonanceDecays", true );
-  fDecayer->init();
+  status &= fDecayer->init();
 
-  return true;
+  return status;
 }