[Bug fortran/31210] New: wrong code generated with gfortran

[jv244 at cam dot ac dot uk]

With a recent gfortran, the following compiles, but generates the wrong
results:

MODULE xml_markups

   LOGICAL, PRIVATE :: should_write_tags=.TRUE.

CONTAINS

   FUNCTION write_xml_tag(tag) RESULT(res)
     CHARACTER(LEN=*), INTENT(IN) :: tag
     CHARACTER(LEN=MERGE(LEN_TRIM(tag),0,should_write_tags)) :: res
     res=tag
   END FUNCTION write_xml_tag

   SUBROUTINE set_write_xml_tags(should_write)
     LOGICAL, INTENT(IN) :: should_write
     should_write_tags=should_write
   END SUBROUTINE

END MODULE xml_markups

USE xml_markups

REAL, PARAMETER :: val=3.1415
character(len=80) :: old,new,new2

! old style write

write(old,'(T2,F12.6)')  val

! new style write
write(new,'(T2,A,F12.6,A)') write_xml_tag("<keword>  "), &
                       val,write_xml_tag("</keyword> ")

! if the use has selected --no-xml-output this should be set early
CALL set_write_xml_tags(.FALSE.)

! new style write with old result
write(new2,'(T2,A,F12.6,A)') write_xml_tag("<keword>  "), &
                       val,write_xml_tag("</keyword> ")

IF (old.NE.new2) CALL ABORT()

END


-- 
           Summary: wrong code generated with gfortran
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jv244 at cam dot ac dot uk


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31210