Hi All,

This patch corrects incorrect results from assignment of unlimited
polymorphic function results both in assignment statements and allocation
with source.

The first chunk in trans-array.cc ensures that the array dtype is set to
the source dtype. The second chunk ensures that the lhs _len field does not
default to zero and so is specific to dynamic types of character.

The addition to trans-stmt.cc transforms the source expression, aka expr3,
from a derived type of type "STAR" into a proper unlimited polymorphic
expression ready for assignment to the newly allocated entity.

OK for mainline?

Paul

Fortran: Fix wrong code in unlimited polymorphic assignment [PR113363]

2024-04-10  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
PR fortran/113363
* trans-array.cc (gfc_array_init_size): Use the expr3 dtype so
that the correct element size is used.
(gfc_alloc_allocatable_for_assignment): Set the _len field for
unlimited polymorphic assignments.
* trans-stmt.cc (gfc_trans_allocate): Build a correct rhs for
the assignment of an unlimited polymorphic 'source'.

gcc/testsuite/
PR fortran/113363
* gfortran.dg/pr113363.f90: New test.