4 files changed, 39 insertions, 3 deletions
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c
index 6566c47..998d4d4 100644
--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -3787,7 +3787,20 @@ gfc_conv_array_ref (gfc_se * se, gfc_array_ref * ar, gfc_expr *expr,
 	decl = sym->backend_decl;
     }
   else if (sym->ts.type == BT_CLASS)
-    decl = NULL_TREE;
+    {
+      if (UNLIMITED_POLY (sym))
+	{
+	  gfc_expr *class_expr = gfc_find_and_cut_at_last_class_ref (expr);
+	  gfc_init_se (&tmpse, NULL);
+	  gfc_conv_expr (&tmpse, class_expr);
+	  if (!se->class_vptr)
+	    se->class_vptr = gfc_class_vptr_get (tmpse.expr);
+	  gfc_free_expr (class_expr);
+	  decl = tmpse.expr;
+	}
+      else
+	decl = NULL_TREE;
+    }
 
   se->expr = build_array_ref (se->expr, offset, decl, se->class_vptr);
 }
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index a690839..2c31ec9 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -728,7 +728,7 @@ gfc_conv_derived_to_class (gfc_se *parmse, gfc_expr *e,
 	  gfc_expr *len;
 	  gfc_se se;
 
-	  len = gfc_copy_expr (e);
+	  len = gfc_find_and_cut_at_last_class_ref (e);
 	  gfc_add_len_component (len);
 	  gfc_init_se (&se, NULL);
 	  gfc_conv_expr (&se, len);
@@ -739,6 +739,7 @@ gfc_conv_derived_to_class (gfc_se *parmse, gfc_expr *e,
 					    integer_zero_node));
 	  else
 	    tmp = se.expr;
+	  gfc_free_expr (len);
 	}
       else
 	tmp = integer_zero_node;
diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index 389fec7..adc6b8f 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/gcc/fortran/trans-stmt.c
@@ -2091,6 +2091,7 @@ trans_associate_var (gfc_symbol *sym, gfc_wrapped_block *block)
 	  /* Obtain a temporary class container for the result.  */
 	  gfc_conv_derived_to_class (&se, e, sym->ts, tmp, false, false);
 	  se.expr = build_fold_indirect_ref_loc (input_location, se.expr);
+	  need_len_assign = false;
 	}
       else
 	{
diff --git a/gcc/fortran/trans.c b/gcc/fortran/trans.c
index ed05426..8caa625 100644
--- a/gcc/fortran/trans.c
+++ b/gcc/fortran/trans.c
@@ -429,7 +429,28 @@ gfc_build_array_ref (tree base, tree offset, tree decl, tree vptr)
   /* If decl or vptr are non-null, pointer arithmetic for the array reference
      is likely. Generate the 'span' for the array reference.  */
   if (vptr)
-    span = gfc_vptr_size_get (vptr);
+    {
+      span = gfc_vptr_size_get (vptr);
+
+      /* Check if this is an unlimited polymorphic object carrying a character
+	 payload. In this case, the 'len' field is non-zero.  */
+      if (decl && GFC_CLASS_TYPE_P (TREE_TYPE (decl)))
+	{
+	  tmp = gfc_class_len_or_zero_get (decl);
+	  if (!integer_zerop (tmp))
+	    {
+	      tree cond;
+	      tree stype = TREE_TYPE (span);
+	      tmp = fold_convert (stype, tmp);
+	      cond = fold_build2_loc (input_location, EQ_EXPR,
+				      logical_type_node, tmp,
+				      build_int_cst (stype, 0));
+	      tmp = fold_build2 (MULT_EXPR, stype, span, tmp);
+	      span = fold_build3_loc (input_location, COND_EXPR, stype,
+				      cond, span, tmp);
+	    }
+	}
+    }
   else if (decl)
     span = get_array_span (type, decl);