[Bug fortran/105205] New: Incorrect assignment of derived type with allocatable, deferred-length character component

["townsend at astro dot wisc.edu" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105205

            Bug ID: 105205
           Summary: Incorrect assignment of derived type with allocatable,
                    deferred-length character component
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: townsend at astro dot wisc.edu
  Target Milestone: ---

I've run into problems with assignment of derived types containing an
allocatable array of deferred-length strings. Example program:

---
program alloc_char_type
   implicit none
   type mytype
      character(:), allocatable :: c(:)
   end type mytype
   type(mytype) :: a
   type(mytype) :: b
   integer :: i
   a%c = ['foo','bar','biz','buz']
   b = a
   do i = 1, size(b%c)
      print *,b%c(i)
   end do
end
---

Running with gfortran 10.2.0 or 11.2.0, I get the output:

>>
 foo



<<

If I hard-code the length of the c component (to, say, 3), I get the expected
output:

>>
 foo
 bar
 biz
 buz
<<

It seems as if only the first element of c is being copied correctly.

cheers,

Rich