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[Bug libfortran/24700] New: Bad write after backing up from end of file
- From: "jvdelisle at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 6 Nov 2005 23:55:05 -0000
- Subject: [Bug libfortran/24700] New: Bad write after backing up from end of file
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
The following program from http://gcc.gnu.org/ml/fortran/2005-11/msg00084.html
incorrectly writesthe 'TEST' file. Thanks to Georgy Salnikov for finding and
submitting this bug.
PROGRAM TEST
CHARACTER*8 TXT
DATA TXT/'**TEST**'/
OPEN (1, FILE='TEST', STATUS='UNKNOWN', FORM='UNFORMATTED')
WRITE (1) TXT
REWIND 1
READ (1, END=1) TXT
READ (1, END=1) TXT
1 CONTINUE
BACKSPACE 1
WRITE (1) TXT
CLOSE (1, STATUS='KEEP')
END
Georgy also submitted a patch which is considered obvious:
diff -Naur gcc-4.0.2.orig/libgfortran/io/transfer.c
gcc-4.0.2/libgfortran/io/transfer.c
--- gcc-4.0.2.orig/libgfortran/io/transfer.c 2005-09-12 01:55:16.000000000
+0700
+++ gcc-4.0.2/libgfortran/io/transfer.c 2005-10-15 12:29:13.000000000 +0700
@@ -1641,11 +1641,13 @@
{
generate_error (ERROR_END, NULL);
current_unit->endfile = AFTER_ENDFILE;
+ current_unit->current_record = 0;
}
break;
case AFTER_ENDFILE:
generate_error (ERROR_ENDFILE, NULL);
+ current_unit->current_record = 0;
break;
}
}
Test results to follow:
--
Summary: Bad write after backing up from end of file
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libfortran
AssignedTo: jvdelisle at gcc dot gnu dot org
ReportedBy: jvdelisle at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24700