--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gfortran.dg/arrayio_0.f90	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,19 @@
+! { dg-do compile }
+! Tests fix for PR20840 - would ICE with vector subscript in 
+! internal unit.
+!
+! Contributed by Paul Thomas  <pault@gcc.gnu.org>
+!
+  character(len=12), dimension(4) :: iu, buff
+  character(len=48), dimension(2) :: iue
+  equivalence (iu, iue)
+  integer, dimension(4) :: v = (/2,1,4,3/)
+  iu = (/"Vector    ","subscripts","not       ","allowed!  "/)
+  read (iu, '(a12/)') buff
+  read (iue(1), '(4a12)') buff
+  read (iu(4:1:-1), '(a12/)') buff
+  read (iu(v), '(a12/)') buff           ! { dg-error "with vector subscript" }
+  read (iu((/2,4,3,1/)), '(a12/)') buff ! { dg-error "with vector subscript" }
+  print *, buff
+  end
+