[Bug fortran/111304] New: Problem when passing implicit arrays of characters to functions

[mailling-lists-bd at posteo dot de via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111304

            Bug ID: 111304
           Summary: Problem when passing implicit arrays of characters to
                    functions
           Product: gcc
           Version: 13.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mailling-lists-bd at posteo dot de
  Target Milestone: ---

Hi,

In the following code, the first call to `func1` works as expected and prints
the content of the array `my_directory`, while the second call, with the array
defined directly in the function argument, leads to SIGABRT and prints 
```
 ARRAY = my_directory/file1my_directory/file2my_directory/dum1
my_directory/dum2
corrupted size vs. prev_size
```

I have tested with gfortran 13.2.1 (gfortran -o test program.f90), on Fedora
38. It should also be noticed that both function calls run fine if we remove
the `trim(prefix)//` from each character string.


```
program test
  implicit none

  character(len=256) :: test_array(4)
  character(len=:), allocatable :: prefix
  integer :: res

  prefix = 'my_directory'
  test_array = [ character(len=256) :: &
       & trim(prefix)//'/file1', &
       & trim(prefix)//'/file2', &
       & trim(prefix)//'/dum1', &
       & trim(prefix)//'/dum2' &
       & ]

  print *, 'Test with "res = func1(test_array)"'
  res = func1(test_array)

  print *, 'Test with "res = func1([ character(len=) :: ...] )"'
  res = func1([ character(len=256) :: &
       & trim(prefix)//'/file1', &
       & trim(prefix)//'/file2', &
       & trim(prefix)//'/dum1', &
       & trim(prefix)//'/dum2' &
       & ])


contains

  function func1(array) result(res)
    character(len=*), intent(in) :: array(:)

    integer :: res

    print *, 'ARRAY = ', array
    res = 0
  end function func1
end program test
```