From c100eff11e8b829171a4d63dac7571d3aa38f7e6 Mon Sep 17 00:00:00 2001 From: Paul Brook Date: Fri, 27 Aug 2004 13:44:52 +0000 Subject: [PATCH] rewind.c (st_rewind): Reset unit to read mode. * io/rewind.c (st_rewind): Reset unit to read mode. testsuite/ * gfortran.dg/rewind_1.f90: New test. From-SVN: r86659 --- gcc/testsuite/ChangeLog | 4 ++++ gcc/testsuite/gfortran.dg/rewind_1.f90 | 18 ++++++++++++++++++ libgfortran/ChangeLog | 4 ++++ libgfortran/io/rewind.c | 5 +++++ 4 files changed, 31 insertions(+) create mode 100644 gcc/testsuite/gfortran.dg/rewind_1.f90 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 18f803758a6..20b62678e28 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2004-08-27 Paul Brook + + * gfortran.dg/rewind_1.f90: New test. + 2004-08-27 Bud Davis PR fortran/16597 diff --git a/gcc/testsuite/gfortran.dg/rewind_1.f90 b/gcc/testsuite/gfortran.dg/rewind_1.f90 new file mode 100644 index 00000000000..cbd2ef17b8f --- /dev/null +++ b/gcc/testsuite/gfortran.dg/rewind_1.f90 @@ -0,0 +1,18 @@ +! { dg-do run } +! Check that rewind doesn't delete a file. +! Writing to the file truncates it at the end of the current record. Out +! IO library was defering the actual truncation until the file was rewound. +! A second rewind would then (incorrectly) think the file had just been +! written to, and truncate the file to zero length. +program foo + character*11 s + open(unit=11, status="SCRATCH") + write(11, '(a11)') "Hello World" + rewind(11) + rewind(11) + s = "" + read(11, '(a11)') s + close(11) + if (s .ne. "Hello World") call abort +end program + diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog index e0039ec0ac9..7f1bff2fef1 100644 --- a/libgfortran/ChangeLog +++ b/libgfortran/ChangeLog @@ -1,3 +1,7 @@ +2004-08-27 Paul Brook + + * io/rewind.c (st_rewind): Reset unit to read mode. + 2004-08-27 Bud Davis PR fortran/16597 diff --git a/libgfortran/io/rewind.c b/libgfortran/io/rewind.c index d9758a6d5ec..7be2328037c 100644 --- a/libgfortran/io/rewind.c +++ b/libgfortran/io/rewind.c @@ -40,8 +40,13 @@ st_rewind (void) "Cannot REWIND a file opened for DIRECT access"); else { + /* If we have been writing to the file, the last written record + is the last record in the file, so trincate the file now. + Reset to read mode so two consecutive rewind statements + don't delete the file contents. */ if (u->mode==WRITING) struncate(u->s); + u->mode = READING; u->last_record = 0; if (sseek (u->s, 0) == FAILURE) generate_error (ERROR_OS, NULL); -- 2.30.2