re PR fortran/62135 (ICE with invalid SELECT CASE selector)

fortran/
	PR fortran/62135
	* resolve.c (resolve_select): Fix list traversal in case the
	last element of the CASE list was dropped as unreachable code.

testsuite/
	PR fortran/62135
	* gfortran.dg/pr62135.f90: New test.

From-SVN: r214351

gcc/fortran/ChangeLog

+2014-08-22  Steven Bosscher  <steven@gcc.gnu.org>
+
+	PR fortran/62135
+	* resolve.c (resolve_select): Fix list traversal in case the
+	last element of the CASE list was dropped as unreachable code.
+
 2014-08-22  Joost VandeVondele  <Joost.VandeVondele@mat.ethz.ch>
 
 	PR fortran/61234

gcc/fortran/resolve.c

@@ -7761,7 +7761,7 @@ resolve_select (gfc_code *code, bool select_type)
 	/* Strip all other unreachable cases.  */
 	if (body->ext.block.case_list)
 	  {
-	    for (cp = body->ext.block.case_list; cp->next; cp = cp->next)
+	    for (cp = body->ext.block.case_list; cp && cp->next; cp = cp->next)
 	      {
 		if (cp->next->unreachable)
 		  {

gcc/testsuite/ChangeLog

+2014-08-22  Steven Bosscher  <steven@gcc.gnu.org>
+
+	PR fortran/62135
+	* gfortran.dg/pr62135.f90: New test.
+
 2014-08-22  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	* g++.dg/warn/wdate-time.C: Remove.

gcc/testsuite/gfortran.dg/pr62135.f90

+! { dg-do compile }
+! { dg-options -Wsurprising }
+
+   PROGRAM PR62135
+      IMPLICIT NONE
+      CHARACTER*1 :: choice
+      choice = 'x'
+      SELECT CASE (choice)
+         ! This triggered an ICE: an unreachable case clause
+         ! as the last of a list.
+         CASE ('2':'7','9':'0') ! { dg-warning "can never be matched" }
+            WRITE(*,*) "barf"
+         CASE DEFAULT
+            CONTINUE
+      END SELECT
+   END PROGRAM PR62135
+