Add a protection in TTreeFormula::EvalInstance in case a null string is found on the file.
Add a protection in TTreeFormula::EvalInstance in case a null string
is found on the file.


git-svn-id: acec3fd5b7ea1eb9e79d6329d318e8118ee2e14f@1516 27541ba8-7e3a-0410-8455-c3a389f83636

esakellari/root,karies/root,pspe/root,Duraznos/root,olifre/root,zzxuanyuan/root,satyarth934/root,smarinac/root,davidlt/root,bbockelm/root,buuck/root,dfunke/root,krafczyk/root,sbinet/cxx-root,CristinaCristescu/root,sirinath/root,gbitzes/root,georgtroska/root,vukasinmilosevic/root,mattkretz/root,sirinath/root,krafczyk/root,BerserkerTroll/root,omazapa/root,omazapa/root-old,dfunke/root,lgiommi/root,buuck/root,lgiommi/root,perovic/root,ffurano/root5,tc3t/qoot,kirbyherm/root-r-tools,georgtroska/root,simonpf/root,mkret2/root,alexschlueter/cern-root,zzxuanyuan/root-compressor-dummy,mkret2/root,sawenzel/root,mkret2/root,bbockelm/root,agarciamontoro/root,thomaskeck/root,krafczyk/root,Y--/root,perovic/root,BerserkerTroll/root,sawenzel/root,mattkretz/root,lgiommi/root,BerserkerTroll/root,strykejern/TTreeReader,pspe/root,zzxuanyuan/root-compressor-dummy,thomaskeck/root,karies/root,pspe/root,Dr15Jones/root,sawenzel/root,omazapa/root,bbockelm/root,agarciamontoro/root,esakellari/my_root_for_test,georgtroska/root,root-mirror/root,ffurano/root5,dfunke/root,tc3t/qoot,0x0all/ROOT,mattkretz/root,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,nilqed/root,gbitzes/root,CristinaCristescu/root,dfunke/root,dfunke/root,sirinath/root,omazapa/root-old,pspe/root,jrtomps/root,lgiommi/root,omazapa/root,sbinet/cxx-root,cxx-hep/root-cern,bbockelm/root,zzxuanyuan/root,satyarth934/root,bbockelm/root,vukasinmilosevic/root,omazapa/root-old,evgeny-boger/root,simonpf/root,lgiommi/root,sirinath/root,arch1tect0r/root,alexschlueter/cern-root,arch1tect0r/root,esakellari/my_root_for_test,sbinet/cxx-root,Duraznos/root,jrtomps/root,nilqed/root,perovic/root,alexschlueter/cern-root,esakellari/my_root_for_test,mkret2/root,evgeny-boger/root,Dr15Jones/root,root-mirror/root,nilqed/root,sawenzel/root,abhinavmoudgil95/root,esakellari/root,ffurano/root5,dfunke/root,sbinet/cxx-root,mkret2/root,sirinath/root,beniz/root,tc3t/qoot,Duraznos/root,omazapa/root-old,smarinac/root,gganis/root,zzxuanyuan/root,veprbl/root,satyarth934/root,evgeny-boger/root,abhinavmoudgil95/root,karies/root,vukasinmilosevic/root,nilqed/root,abhinavmoudgil95/root,tc3t/qoot,karies/root,alexschlueter/cern-root,buuck/root,sawenzel/root,Y--/root,vukasinmilosevic/root,Duraznos/root,Y--/root,zzxuanyuan/root-compressor-dummy,0x0all/ROOT,nilqed/root,tc3t/qoot,dfunke/root,arch1tect0r/root,buuck/root,0x0all/ROOT,mattkretz/root,bbockelm/root,jrtomps/root,perovic/root,agarciamontoro/root,Duraznos/root,beniz/root,root-mirror/root,arch1tect0r/root,olifre/root,arch1tect0r/root,davidlt/root,smarinac/root,gbitzes/root,omazapa/root-old,gganis/root,simonpf/root,evgeny-boger/root,jrtomps/root,krafczyk/root,pspe/root,esakellari/root,alexschlueter/cern-root,ffurano/root5,olifre/root,krafczyk/root,georgtroska/root,dfunke/root,Dr15Jones/root,nilqed/root,omazapa/root,strykejern/TTreeReader,lgiommi/root,omazapa/root,karies/root,buuck/root,esakellari/root,jrtomps/root,BerserkerTroll/root,pspe/root,agarciamontoro/root,sbinet/cxx-root,simonpf/root,zzxuanyuan/root,ffurano/root5,CristinaCristescu/root,perovic/root,gbitzes/root,0x0all/ROOT,zzxuanyuan/root-compressor-dummy,kirbyherm/root-r-tools,beniz/root,agarciamontoro/root,simonpf/root,veprbl/root,CristinaCristescu/root,lgiommi/root,perovic/root,georgtroska/root,abhinavmoudgil95/root,zzxuanyuan/root,karies/root,buuck/root,mattkretz/root,olifre/root,karies/root,BerserkerTroll/root,arch1tect0r/root,sbinet/cxx-root,esakellari/my_root_for_test,sbinet/cxx-root,evgeny-boger/root,bbockelm/root,karies/root,omazapa/root-old,Y--/root,beniz/root,sirinath/root,perovic/root,satyarth934/root,satyarth934/root,sbinet/cxx-root,Dr15Jones/root,esakellari/root,arch1tect0r/root,Y--/root,evgeny-boger/root,CristinaCristescu/root,omazapa/root-old,buuck/root,simonpf/root,pspe/root,vukasinmilosevic/root,abhinavmoudgil95/root,thomaskeck/root,zzxuanyuan/root,root-mirror/root,perovic/root,cxx-hep/root-cern,mattkretz/root,olifre/root,krafczyk/root,BerserkerTroll/root,Dr15Jones/root,mhuwiler/rootauto,BerserkerTroll/root,ffurano/root5,zzxuanyuan/root,omazapa/root-old,gbitzes/root,Y--/root,root-mirror/root,satyarth934/root,olifre/root,smarinac/root,gbitzes/root,perovic/root,veprbl/root,root-mirror/root,satyarth934/root,sawenzel/root,zzxuanyuan/root-compressor-dummy,satyarth934/root,strykejern/TTreeReader,omazapa/root,kirbyherm/root-r-tools,davidlt/root,mattkretz/root,root-mirror/root,tc3t/qoot,vukasinmilosevic/root,krafczyk/root,kirbyherm/root-r-tools,zzxuanyuan/root,lgiommi/root,CristinaCristescu/root,root-mirror/root,georgtroska/root,lgiommi/root,georgtroska/root,davidlt/root,satyarth934/root,sawenzel/root,lgiommi/root,dfunke/root,Duraznos/root,Duraznos/root,zzxuanyuan/root-compressor-dummy,mattkretz/root,thomaskeck/root,jrtomps/root,veprbl/root,veprbl/root,beniz/root,zzxuanyuan/root,dfunke/root,abhinavmoudgil95/root,olifre/root,tc3t/qoot,vukasinmilosevic/root,vukasinmilosevic/root,kirbyherm/root-r-tools,BerserkerTroll/root,Dr15Jones/root,sirinath/root,jrtomps/root,davidlt/root,mkret2/root,strykejern/TTreeReader,agarciamontoro/root,simonpf/root,zzxuanyuan/root,cxx-hep/root-cern,beniz/root,sirinath/root,evgeny-boger/root,smarinac/root,esakellari/my_root_for_test,veprbl/root,Y--/root,sirinath/root,0x0all/ROOT,vukasinmilosevic/root,smarinac/root,esakellari/my_root_for_test,omazapa/root,davidlt/root,esakellari/my_root_for_test,mhuwiler/rootauto,krafczyk/root,esakellari/my_root_for_test,zzxuanyuan/root-compressor-dummy,smarinac/root,abhinavmoudgil95/root,gbitzes/root,nilqed/root,thomaskeck/root,omazapa/root-old,mhuwiler/rootauto,esakellari/my_root_for_test,agarciamontoro/root,krafczyk/root,omazapa/root-old,thomaskeck/root,veprbl/root,georgtroska/root,olifre/root,mhuwiler/rootauto,pspe/root,olifre/root,omazapa/root-old,abhinavmoudgil95/root,zzxuanyuan/root-compressor-dummy,gbitzes/root,lgiommi/root,Duraznos/root,vukasinmilosevic/root,beniz/root,jrtomps/root,BerserkerTroll/root,olifre/root,gganis/root,sawenzel/root,smarinac/root,esakellari/root,nilqed/root,georgtroska/root,thomaskeck/root,gganis/root,root-mirror/root,cxx-hep/root-cern,smarinac/root,pspe/root,CristinaCristescu/root,gbitzes/root,Duraznos/root,sbinet/cxx-root,sirinath/root,bbockelm/root,tc3t/qoot,mkret2/root,evgeny-boger/root,Duraznos/root,mhuwiler/rootauto,mkret2/root,gbitzes/root,cxx-hep/root-cern,gbitzes/root,perovic/root,zzxuanyuan/root-compressor-dummy,alexschlueter/cern-root,veprbl/root,evgeny-boger/root,alexschlueter/cern-root,olifre/root,simonpf/root,omazapa/root,thomaskeck/root,sawenzel/root,Y--/root,esakellari/my_root_for_test,gganis/root,mkret2/root,perovic/root,esakellari/root,ffurano/root5,0x0all/ROOT,davidlt/root,davidlt/root,gganis/root,root-mirror/root,arch1tect0r/root,veprbl/root,sbinet/cxx-root,mhuwiler/rootauto,agarciamontoro/root,beniz/root,buuck/root,mhuwiler/rootauto,cxx-hep/root-cern,sirinath/root,zzxuanyuan/root,Y--/root,thomaskeck/root,satyarth934/root,mattkretz/root,buuck/root,strykejern/TTreeReader,arch1tect0r/root,karies/root,esakellari/root,CristinaCristescu/root,veprbl/root,agarciamontoro/root,evgeny-boger/root,agarciamontoro/root,evgeny-boger/root,omazapa/root,georgtroska/root,kirbyherm/root-r-tools,davidlt/root,simonpf/root,karies/root,0x0all/ROOT,mhuwiler/rootauto,omazapa/root,zzxuanyuan/root,Y--/root,esakellari/root,cxx-hep/root-cern,karies/root,strykejern/TTreeReader,cxx-hep/root-cern,jrtomps/root,Y--/root,bbockelm/root,arch1tect0r/root,strykejern/TTreeReader,satyarth934/root,davidlt/root,abhinavmoudgil95/root,gganis/root,root-mirror/root,dfunke/root,beniz/root,buuck/root,simonpf/root,vukasinmilosevic/root,pspe/root,beniz/root,sawenzel/root,gganis/root,CristinaCristescu/root,sbinet/cxx-root,jrtomps/root,simonpf/root,mkret2/root,nilqed/root,abhinavmoudgil95/root,mkret2/root,tc3t/qoot,gganis/root,gganis/root,esakellari/root,davidlt/root,0x0all/ROOT,arch1tect0r/root,mhuwiler/rootauto,georgtroska/root,jrtomps/root,CristinaCristescu/root,bbockelm/root,sawenzel/root,mhuwiler/rootauto,kirbyherm/root-r-tools,BerserkerTroll/root,mhuwiler/rootauto,tc3t/qoot,nilqed/root,bbockelm/root,veprbl/root,smarinac/root,BerserkerTroll/root,gganis/root,abhinavmoudgil95/root,agarciamontoro/root,nilqed/root,pspe/root,buuck/root,Duraznos/root,0x0all/ROOT,esakellari/root,thomaskeck/root,krafczyk/root,mattkretz/root,beniz/root,omazapa/root,krafczyk/root,mattkretz/root,CristinaCristescu/root,Dr15Jones/root