Check the presence of the ExB field map

before trying to create new
(Marian)

diff --git a/TPC/AliTPC.cxx b/TPC/AliTPC.cxx
index a63f9af9f0eef15a931b5d7cacfbfc6144b0c7e0..fd06436ad8a55a867a145017fbc99ec0295b3783 100644 (file)
--- a/TPC/AliTPC.cxx
+++ b/TPC/AliTPC.cxx
@@ -1801,9 +1801,11 @@ void AliTPC::MakeSector(Int_t isec,Int_t nrows,TTree *TH,
   //-----------------------------------------------------------------
   AliTPCcalibDB* const calib=AliTPCcalibDB::Instance();
   if (gAlice){ // Set correctly the magnetic field in the ExB calculation
-    AliMagF * field = ((AliMagF*)TGeoGlobalMagField::Instance()->GetField());
-    if (field) {
-      calib->SetExBField(field);
+    if (!calib->GetExB()){
+      AliMagF * field = ((AliMagF*)TGeoGlobalMagField::Instance()->GetField()); 
+      if (field) {
+       calib->SetExBField(field);
+      }
     }
   }