| Message ID | 87bkakx3b0.fsf@oldenburg.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | libio: Check remaining buffer size in _IO_wdo_write (bug 31183) | expand |
On Dez 20 2023, Florian Weimer wrote: > The multibyte character needs to fit into the remaining buffer space, > not the already-written buffer space. Without the fix, we were never > moving the write pointer from the start of the buffer, always using > the single-character fallback buffer. > > Fixes commit 04b76b5aa8b2d1d19066e42dd1 ("Don't error out writing > a multibyte character to an unbuffered stream (bug 17522)"). Ok. I don't know how I managed to get that so wrong.
diff --git a/libio/wfileops.c b/libio/wfileops.c index f16f6db1c3..9ab8f2e7f3 100644 --- a/libio/wfileops.c +++ b/libio/wfileops.c @@ -55,7 +55,7 @@ _IO_wdo_write (FILE *fp, const wchar_t *data, size_t to_do) char mb_buf[MB_LEN_MAX]; char *write_base, *write_ptr, *buf_end; - if (fp->_IO_write_ptr - fp->_IO_write_base < sizeof (mb_buf)) + if (fp->_IO_buf_end - fp->_IO_write_ptr < sizeof (mb_buf)) { /* Make sure we have room for at least one multibyte character. */
The multibyte character needs to fit into the remaining buffer space, not the already-written buffer space. Without the fix, we were never moving the write pointer from the start of the buffer, always using the single-character fallback buffer. Fixes commit 04b76b5aa8b2d1d19066e42dd1 ("Don't error out writing a multibyte character to an unbuffered stream (bug 17522)"). --- libio/wfileops.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: 61bac1a9d2ab80ebcbc51484722e6ea43414bec7