With a recent gfortran, the following compiles, but generates the wrong results:
character(len=20) :: b ! write something no advance open(10,FILE="fort.10",POSITION="REWIND") write(10, '(a,t1,a)',advance='no') 'XXXXXX', 'ABC' close(10) ! append some data open(10,FILE="fort.10",POSITION="APPEND") write(10, '(a)') 'DEF' close(10) ! check what is in the first record open(10,FILE="fort.10",POSITION="REWIND") read(10,'(a)') b IF (b.NE."ABCXXX") 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=31207