[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

Thomas Koenig <tkoenig at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Wrong length in I/O         |Concatenation with deferred
                   |deferred allocatable scalar |length character with lhs
                   |character                   |variable

--- Comment #1 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2011-01-28 20:58:49 UTC ---
Actually, it isn't a wrong length, the problem was an
invisible nul character in the output.

Look at this:

program main
  implicit none
  integer :: i
  character(:), allocatable :: a, b, c
  a = 'a'
  a = a // 'x'
  b = 'b'
  c = b // 'x'
  write (*,*) 'a is:'
  do i=1,len(a)
    write (*,*) ichar(a(i:i))
  end do

  write (*,*) 'c is:'
  do i=1,len(c)
     write (*,*) ichar(c(i:i))
  end do
end program main
ig25@linux-fd1f:~/Krempel/Char-alloc> gfortran bar.f90
ig25@linux-fd1f:~/Krempel/Char-alloc> ./a.out
 a is:
          97
           0
 c is:
          98
         120

The expression a = a // 'x' gets the wrong value for x.