[Bug fortran/65925] New: Memory leak with source allocation nested inside the source of another source allocation

["damian at sourceryinstitute dot org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65925

            Bug ID: 65925
           Summary: Memory leak with source allocation nested inside the
                    source of another source allocation
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: damian at sourceryinstitute dot org
  Target Milestone: ---

Valgrind reports a memory leak with the code below for gfortran 6.0.0 (and 4.10
and 5.0.0):

$ cat reduced-gforLeak.f90 
type IndexSpace
end type
type,extends(IndexSpace) :: OuterProductSpace
end type
type base
  class(IndexSpace),allocatable :: b
end type
type,extends(base) :: subdata
endtype
class(base),allocatable :: d
allocate(d,source = newData())
contains
   type(subdata) function newData() 
      allocate(newData%base%b,source = OuterProductSpace())
   end function
end
$ gfortran reduced-gforLeak.f90 
$ valgrind ./a.out
==3960== Memcheck, a memory error detector
==3960== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==3960== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==3960== Command: ./a.out
==3960== 
==3960== 
==3960== HEAP SUMMARY:
==3960==     in use at exit: 17 bytes in 3 blocks
==3960==   total heap usage: 28 allocs, 25 frees, 12,692 bytes allocated
==3960== 
==3960== LEAK SUMMARY:
==3960==    definitely lost: 17 bytes in 2 blocks
==3960==    indirectly lost: 0 bytes in 1 blocks
==3960==      possibly lost: 0 bytes in 0 blocks
==3960==    still reachable: 0 bytes in 0 blocks
==3960==         suppressed: 0 bytes in 0 blocks
==3960== Rerun with --leak-check=full to see details of leaked memory
==3960== 
==3960== For counts of detected and suppressed errors, rerun with: -v
==3960== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)
$ gfortran --version
GNU Fortran (GCC) 6.0.0 20150422 (experimental)