[Bug libfortran/40334] New: 4.5 regression: changed BACKSPACE behaviour at end of file.

["bartoldeman at users dot sourceforge dot net" <gcc-bugzilla at gcc dot gnu dot org>]

The following program (also attached) reads to eof, backspace, reads (eof
detected), backspace, and reads again. The last read gets the last line with
gfortran 4.5 (tested: r148116) but eof with gfortran <= 4.4, g95, g77 and Sun
f95.

>From reading comp.lang.fortran I know that EOF/BACKSPACE interaction can be
problematic but I'd still hope this would work to be consistent with the other
compilers.

      PROGRAM TEST
      IMPLICIT NONE
      CHARACTER(LEN=5) :: STR
      OPEN(2,FILE='fort.2',ACCESS='sequential')
      WRITE(2,'(A)')'HELLO'
      REWIND(2)

      DO
         READ(2,'(A)',END=1) STR
         PRINT *,STR
      ENDDO
 1    BACKSPACE 2
      !the file pointer is now at EOF

      READ(2,*,END=2) STR
      PRINT *,'error1: not at eof',str
      STOP
 2    BACKSPACE 2
      !the file pointer is now at EOF

      READ(2,'(A)',END=3) STR
      PRINT *,'error2: not at eof'
      STOP
 3    PRINT *,'correct'
      END


-- 
           Summary: 4.5 regression: changed BACKSPACE behaviour at end of
                    file.
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bartoldeman at users dot sourceforge dot net
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40334