glibc/libio
Zack Weinberg 2cc7bad0ae [BZ 1190] Make EOF sticky in stdio.
C99 specifies that the EOF condition on a file is "sticky": once EOF
has been encountered, all subsequent reads should continue to return
EOF until the file is closed or something clears the "end-of-file
indicator" (e.g. fseek, clearerr).  This is arguably a change from
C89, where the wording was ambiguous; the BSDs always had sticky EOF,
but the System V lineage would attempt to read from the underlying fd
again.  GNU libc has followed System V for as long as we've been
using libio, but nowadays C99 conformance and BSD compatibility are
more important than System V compatibility.

You might wonder if changing the _underflow impls is sufficient to
apply the C99 semantics to all of the many stdio functions that
perform input.  It should be enough to cover all paths to _IO_SYSREAD,
and the only other functions that call _IO_SYSREAD are the _seekoff
impls, which is OK because seeking clears EOF, and the _xsgetn impls,
which, as far as I can tell, are unused within glibc.

The test programs in this patch use a pseudoterminal to set up the
necessary conditions.  To facilitate this I added a new test-support
function that sets up a pair of pty file descriptors for you; it's
almost the same as BSD openpty, the only differences are that it
allocates the optionally-returned tty pathname with malloc, and that
it crashes if anything goes wrong.

	[BZ #1190]
        [BZ #19476]
	* libio/fileops.c (_IO_new_file_underflow): Return EOF immediately
	if the _IO_EOF_SEEN bit is already set; update commentary.
	* libio/oldfileops.c (_IO_old_file_underflow): Likewise.
	* libio/wfileops.c (_IO_wfile_underflow): Likewise.

	* support/support_openpty.c, support/tty.h: New files.
	* support/Makefile (libsupport-routines): Add support_openpty.

	* libio/tst-fgetc-after-eof.c, wcsmbs/test-fgetwc-after-eof.c:
	New test cases.
	* libio/Makefile (tests): Add tst-fgetc-after-eof.
	* wcsmbs/Makefile (tests): Add tst-fgetwc-after-eof.
2018-03-13 08:31:56 -04:00
..
bits Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
__fbufsize.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__flbf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__fpending.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__fpurge.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__freadable.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__freading.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__fsetlocking.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__fwritable.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__fwriting.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bug-fopena+.c
bug-fseek.c
bug-ftell.c
bug-memstream1.c Add missing header files throughout the testsuite. 2017-02-16 17:33:18 -05:00
bug-mmap-fflush.c
bug-rewind2.c
bug-rewind.c
bug-ungetc2.c
bug-ungetc3.c
bug-ungetc4.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bug-ungetc.c
bug-ungetwc1.c
bug-ungetwc2.c
bug-wfflush.c
bug-wmemstream1.c Add missing header files throughout the testsuite. 2017-02-16 17:33:18 -05:00
bug-wsetpos.c
clearerr_u.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
clearerr.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
Depend
fcloseall.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
feof_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
feof.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ferror_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ferror.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
filedoalloc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fileno.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fileops.c [BZ 1190] Make EOF sticky in stdio. 2018-03-13 08:31:56 -04:00
fmemopen.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fputc_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fputc.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
fputwc_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fputwc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
freopen64.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
freopen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fseek.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fseeko64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fseeko.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ftello64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ftello.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fwide.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
fwprintf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fwscanf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
genops.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
getc_u.c Fix -Os getc_unlocked linknamespace, localplt issues (bug 15105, bug 19463). 2018-02-21 18:01:11 +00:00
getc.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getchar_u.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getchar.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
getwc_u.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getwc.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getwchar_u.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
getwchar.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
iofclose.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
iofdopen.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
iofflush_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofflush.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofgetpos64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofgetpos.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofgets_u.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
iofgets.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
iofgetws_u.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
iofgetws.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
iofopen64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofopen.c Remove legacy configuration knobs from libio. 2018-02-21 14:13:21 -05:00
iofopncook.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofputs_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofputs.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofputws_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofputws.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofread_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofread.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofsetpos64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofsetpos.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ioftell.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofwide.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofwrite_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iofwrite.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iogetdelim.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
iogetline.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iogets.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
iogetwline.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iolibio.h Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
iopadn.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iopopen.c Remove legacy configuration knobs from libio. 2018-02-21 14:13:21 -05:00
ioputs.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ioseekoff.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ioseekpos.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iosetbuffer.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iosetvbuf.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
ioungetc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
ioungetwc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iovdprintf.c Remove legacy configuration knobs from libio. 2018-02-21 14:13:21 -05:00
iovsprintf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iovsscanf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iovswscanf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
iowpadn.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
libc_fatal.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
libio.h Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
libioP.h Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
Makefile [BZ 1190] Make EOF sticky in stdio. 2018-03-13 08:31:56 -04:00
memstream.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
obprintf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldfileops.c [BZ 1190] Make EOF sticky in stdio. 2018-03-13 08:31:56 -04:00
oldfmemopen.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldiofclose.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
oldiofdopen.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
oldiofgetpos64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldiofgetpos.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldiofopen.c Remove legacy configuration knobs from libio. 2018-02-21 14:13:21 -05:00
oldiofsetpos64.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldiofsetpos.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldiopopen.c Remove legacy configuration knobs from libio. 2018-02-21 14:13:21 -05:00
oldpclose.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
oldstdfiles.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
oldtmpfile.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
pclose.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
peekc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
putc_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
putc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
putchar_u.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
putchar.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
putwc_u.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
putwc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
putwchar_u.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
putwchar.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
rewind.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
setbuf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
setlinebuf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
stdfiles.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
stdio.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
stdio.h Don't install libio.h or _G_config.h. 2018-02-07 10:07:31 -05:00
strfile.h Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
strops.c Remove _IO_file_flags define. 2018-02-21 14:22:50 -05:00
swprintf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
swscanf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-fmemopen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-freopen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-freopen.sh Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst_getwc.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst_getwc.input
tst_putwc.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst_swprintf.c
tst_swscanf.c
tst_wprintf2.c
tst_wprintf.c
tst_wscanf.c
tst_wscanf.input
tst-atime.c
tst-bz22415.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-eof.c
tst-ext2.c
tst-ext.c
tst-fgetc-after-eof.c [BZ 1190] Make EOF sticky in stdio. 2018-03-13 08:31:56 -04:00
tst-fgetwc.c
tst-fgetwc.input
tst-fgetws.c
tst-fopenloc2.c
tst-fopenloc.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-fputws.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-freopen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-fseek.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-ftell-active-handler.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-ftell-append.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-ftell-partial-wide.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-fwrite-error.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-memstream1.c Add missing header files throughout the testsuite. 2017-02-16 17:33:18 -05:00
tst-memstream2.c Add missing header files throughout the testsuite. 2017-02-16 17:33:18 -05:00
tst-memstream3.c libio: Rename _FWRITE to FWRITE_FUNC 2018-01-29 23:00:17 +01:00
tst-mmap2-eofsync.c 2016-06-11 Paul Pluzhnikov <ppluzhnikov@google.com> 2016-06-11 14:50:16 -07:00
tst-mmap-eofsync.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
tst-mmap-fflushsync.c
tst-mmap-offend.c
tst-mmap-setvbuf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-popen1.c
tst-setvbuf1.c
tst-sscanf.c
tst-swscanf.c
tst-ungetwc1.c
tst-ungetwc2.c
tst-widetext.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-widetext.input Finish change from “Bengali” to “Bangla” 2017-09-09 12:41:54 +02:00
tst-wmemstream1.c
tst-wmemstream2.c
tst-wmemstream3.c libio: Rename _FWRITE to FWRITE_FUNC 2018-01-29 23:00:17 +01:00
vasprintf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
Versions Single threaded stdio optimization 2017-07-04 16:05:12 +01:00
vscanf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
vsnprintf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
vswprintf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
vtables.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
vwprintf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
vwscanf.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
wfiledoalloc.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
wfileops.c [BZ 1190] Make EOF sticky in stdio. 2018-03-13 08:31:56 -04:00
wgenops.c Remove miscellaneous debris from libio. 2018-02-21 14:39:54 -05:00
wmemstream.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
wprintf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
wscanf.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
wstrops.c Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00