--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gfortran.dg/achar_4.f90	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,21 @@
+! { dg-do run }
+! { dg-options "-fbounds-check" }
+! Tests the fix for PR31257, in which achar caused an ICE because it had no
+! charlen.
+!
+! The code comes from http://www.star.le.ac.uk/~cgp/fortran.html (by Clive Page)
+! Reported by Thomas Koenig <tkoenig@gcc.gnu.org>
+!
+  if (any (Up ("AbCdEfGhIjKlM") .ne. (/"ABCDEFGHIJKLM"/))) call abort ()
+contains
+  Character (len=20) Function Up (string)
+    Character(len=*) string
+    Up =                                                                &
+     transfer(merge(achar(iachar(transfer(string,"x",len(string)))-     &
+     (ichar('a')-ichar('A')) ),                                         &
+     transfer(string,"x",len(string)) ,                                 &
+     transfer(string,"x",len(string)) >= "a" .and.                      &
+     transfer(string,"x",len(string)) <= "z"), repeat("x", len(string)))
+    return
+  end function Up
+end