lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-08-07 06:43:00 +03:00
Code Activity

Make fflush (NULL) flush input files (bug 32369)

Browse Source 
As discussed in bug 32369 and required by POSIX, the POSIX feature
fflush (NULL) should flush input files, not just output files.  The
POSIX requirement is that "fflush() shall perform this flushing action
on all streams for which the behavior is defined above", and the
definition for input files is for "a stream open for reading with an
underlying file description, if the file is not already at EOF, and
the file is one capable of seeking".

Implement this requirement in glibc.  (The underlying flushing
implementation is what deals with avoiding errors for seeking on an
unseekable file.)

Tested for x86_64.
This commit is contained in:
Joseph Myers
2025-01-28 21:53:49 +00:00
parent be6818be31
commit 94251ae99e
3 changed files with 102 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
libio/genops.c
View File

@@ -730,6 +730,13 @@ _IO_flush_all (void)
)
&& _IO_OVERFLOW (fp, EOF) == EOF)
result = EOF;
if (_IO_fileno (fp) >= 0
&& ((fp->_mode <= 0 && fp->_IO_read_ptr < fp->_IO_read_end)
|| (_IO_vtable_offset (fp) == 0
&& fp->_mode > 0 && (fp->_wide_data->_IO_read_ptr
< fp->_wide_data->_IO_read_end)))
&& _IO_SYNC (fp) != 0)
result = EOF;
_IO_funlockfile (fp);
run_fp = NULL;