[Bug fortran/99711] Crash when reading an allocated character array in namelist

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99711

--- Comment #10 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Wed, Mar 24, 2021 at 05:35:31AM +0000, sgk at troutmask dot
apl.washington.edu wrote:
>
> What does -ftree-dump-original show?  I wonder if gfortran is doing a
> re-allocation on assignment when it shouldn't.
> 

Nope.  It looks like a counting problem.  Here's a modified
testcase.

   program allocnml
   implicit none
   character(len=:), dimension(:), allocatable :: cbulist_ru
   integer :: iluseg
   namelist /nam_bu_ru/ cbulist_ru
   allocate( character(len=10) :: cbulist_ru(4) )
   cbulist_ru = 'abc'
   print *, size(cbulist_ru), len(cbulist_ru(1))
   open(newunit=iluseg, file='list.nml', status='old')
   read(unit=iluseg, nml=nam_bu_ru)
   print *, size(cbulist_ru), len(cbulist_ru(1))
   print *, cbulist_ru
   print *, '>'//cbulist_ru(1)//'<'
   print *, '>'//cbulist_ru(2)//'<'
   print *, '>'//cbulist_ru(3)//'<'
   print *, '>'//cbulist_ru(4)//'<'
   close(unit=iluseg)
   end program allocnml

I get

% gfcx -o z -O a.f90 && ./z
           4          10
           4          10
 VTURB     abc       abc       abc       
 >VTURB     <
 >abc       <
 >abc       <
 >abc       <

which suggests that during the READ, the individual array
elements aren't assigned.  That is, the array index is 
never incremented from 1 to 4.