Add test case for PR 97799.

gcc/testsuite/ChangeLog:

	* gfortran.dg/entry_23.f: New test.

(cherry picked from commit 3c3beb1)

gcc/testsuite/gfortran.dg/entry_23.f

@@ -0,0 +1,57 @@
+! { dg-do run }
+! PR 97799 - this used to segfault intermittently.
+! Test case by George Hockney.
+      PROGRAM MAIN
+      IMPLICIT NONE
+
+      character *(20) CA(4)  ! four cells of length 20
+
+      call CHAR_ENTRY(CA)  ! call char_sub through entry
+
+      write (*,*) CA       ! write result -- not needed for bug
+      call CHAR_SUB(CA)    ! call char_sb directly -- not needed
+      write (*,*) CA       ! write result -- not needed for bug
+      STOP
+      END
+
+
+
+      SUBROUTINE CHAR_SUB(CARRAY)  ! sets carray cells to 'Something'
+      IMPLICIT NONE
+
+      CHARACTER*(*)       CARRAY(*)
+
+      integer i
+      integer nelts
+
+      nelts = 4    ! same as size of array in main program
+      write (*,*) 'CHAR_SUB'
+      write (*,*) 'len(carray(1))', len(carray(1)) ! len is OK at 20
+      call flush() ! since the next loop segfaults
+      do 1 i=1, nelts  
+         CARRAY(i) = 'Something'
+  1   continue
+      RETURN
+      END
+
+
+      SUBROUTINE             TOP_ENTRY
+!
+! TOP_ENTRY is never called directly.  It organizes entry points
+! and sometimes saves variables for other entry points.  Its
+! signature does not matter for the failure
+!
+      IMPLICIT NONE
+!
+! Declare input variables for all entry points.  Just one here
+!
+      CHARACTER*(*)       CARRAY(*)
+!
+!  Entry point CHAR_ENTRY
+!
+      ENTRY  CHAR_ENTRY( CARRAY)
+      CALL   CHAR_SUB(CARRAY)
+      RETURN
+
+      END SUBROUTINE TOP_ENTRY
+