1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/alloc_comp_assign_3.f90 b/gcc/testsuite/gfortran.dg/alloc_comp_assign_3.f90
new file mode 100644
index 000000000..5be6bd990
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/alloc_comp_assign_3.f90
@@ -0,0 +1,36 @@
+! { dg-do run }
+! Test assignments of nested derived types with allocatable components(PR 20541).
+!
+! Contributed by Erik Edelmann  <eedelmann@gcc.gnu.org>
+!            and Paul Thomas  <pault@gcc.gnu.org>
+!
+  type :: a
+    integer, allocatable :: i(:)
+  end type a
+
+  type :: b
+    type (a), allocatable :: at(:)
+  end type b
+
+  type(a) :: x(2)
+  type(b) :: y(2), z(2)
+  integer i, m(4)
+
+  x(1) = a((/1,2,3,4/))
+  x(2) = a((/1,2,3,4/)+10)
+
+  y(1) = b((/x(1),x(2)/))
+  y(2) = b((/x(2),x(1)/))
+
+  y(2) = y(1)
+  forall (j=1:2,k=1:4, y(1)%at(j)%i(k) .ne. y(2)%at(j)%i(k)) &
+                             y(1)%at(j)%i(k) = 999
+  if (any ((/((y(1)%at(j)%i(k), k=1,4),j=1,2)/) .eq. 999)) call abort ()
+
+
+  z = y
+  forall (i=1:2,j=1:2,k=1:4, z(i)%at(j)%i(k) .ne. y(i)%at(j)%i(k)) &
+                             z(i)%at(j)%i(k) = 999
+  if (any ((/(((z(i)%at(j)%i(k), k=1,4),j=1,2),i=1,2)/) .eq. 999)) call abort ()
+
+end