Protection against empty histogram.

AliTPCPreprocesorOffline  was failing in case the TPC was not include in data acquisition

diff --git a/TPC/AliTPCcalibGainMult.cxx b/TPC/AliTPCcalibGainMult.cxx
index f12e22b8b99d8b542faa730f98ee8c62aa8f109d..0ec6c5e12702b7f5d28882f797e49be51cfbe1e4 100644 (file)
--- a/TPC/AliTPCcalibGainMult.cxx
+++ b/TPC/AliTPCcalibGainMult.cxx
@@ -1790,6 +1790,8 @@ TGraphErrors* AliTPCcalibGainMult::GetGainPerChamber(Int_t padRegion/*=1*/, Bool
 
   if (padRegion<0||padRegion>2) return 0x0;
   
+  if (!fHistGainSector) return NULL;
+  if (!fHistGainSector->GetAxis(2)) return NULL;
   fHistGainSector->GetAxis(2)->SetRangeUser(padRegion,padRegion);
   TH2D * histGainSec = fHistGainSector->Projection(0,1);
 //   TH1D* proj=fHistGainSector->Projection(0);