From e2bddf811ad12c11b37a16097ff0362c24d2ae57 Mon Sep 17 00:00:00 2001
From: morsch <morsch@f7af4fe6-9843-0410-8265-dc069ae4e863>
Date: Tue, 18 Nov 2003 10:03:38 +0000
Subject: [PATCH] Some protections needed for stand-allone use added.

---
 PYTHIA6/AliGenPythia.cxx | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/PYTHIA6/AliGenPythia.cxx b/PYTHIA6/AliGenPythia.cxx
index 5c9f412364a..346e299a2b8 100644
--- a/PYTHIA6/AliGenPythia.cxx
+++ b/PYTHIA6/AliGenPythia.cxx
@@ -153,6 +153,8 @@ void AliGenPythia::Init()
     
     SetMC(AliPythia::Instance());
     fPythia=(AliPythia*) fMCEvGen;
+    printf("Pythia Init %p", fPythia);
+    
 //
     fParentWeight=1./Float_t(fNpart);
 //
@@ -313,7 +315,7 @@ void AliGenPythia::Generate()
 	if (fQuench) {
 	    fPythia->SetMSTJ(1, 0);
 	}
-
+	printf("Pythia pyevnt %p", fPythia);
 	fPythia->Pyevnt();
 
 	if (fQuench) {
@@ -322,11 +324,13 @@ void AliGenPythia::Generate()
 	    fPythia->Pyexec();
 	}
 	
+	if (gAlice) {
+	    if (gAlice->GetEvNumber()>=fDebugEventFirst &&
+		gAlice->GetEvNumber()<=fDebugEventLast) fPythia->Pylist(1);
+	}
 	
-	if (gAlice->GetEvNumber()>=fDebugEventFirst &&
-	    gAlice->GetEvNumber()<=fDebugEventLast) fPythia->Pylist(1);
 	fTrials++;
-	
+	printf("Pythia import t %p %p ", fPythia, fParticles);
 	fPythia->ImportParticles(fParticles,"All");
 
 	Boost();
@@ -627,11 +631,13 @@ void AliGenPythia::AdjustWeights()
 {
 // Adjust the weights after generation of all events
 //
-    TParticle *part;
-    Int_t ntrack=gAlice->GetMCApp()->GetNtrack();
-    for (Int_t i=0; i<ntrack; i++) {
-	part= gAlice->GetMCApp()->Particle(i);
-	part->SetWeight(part->GetWeight()*fKineBias);
+    if (gAlice) {
+	TParticle *part;
+	Int_t ntrack=gAlice->GetMCApp()->GetNtrack();
+	for (Int_t i=0; i<ntrack; i++) {
+	    part= gAlice->GetMCApp()->Particle(i);
+	    part->SetWeight(part->GetWeight()*fKineBias);
+	}
     }
 }
     
@@ -672,7 +678,7 @@ void AliGenPythia::MakeHeader()
 							jets[3][i]);
 	}
     }
-    gAlice->SetGenEventHeader(fHeader);
+    if (gAlice) gAlice->SetGenEventHeader(fHeader);
 }
 	
 
-- 
2.31.1