https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67614
--- Comment #1 from Gerhard Steinmetz <gerhard.steinmetz.fort...@t-online.de> --- $ cat z4.f90 program p integer, pointer :: z => null() if ( z ) 1, 2, 3 1 stop 1 2 stop 2 3 stop 3 end $ gfortran -g -O0 -Wall -fcheck=all -fno-frontend-optimize z4.f90 $ a.out Program received signal SIGSEGV: Segmentation fault - invalid memory reference.