[v2] libio: do not cleanup wide buffers of legacy standard files [BZ #24228]
Commit Message
Commit glibc-2.23~693 (a601b74d31ca086de38441d316a3dee24c866305)
introduced a regression: _IO_unbuffer_all() now invokes _IO_wsetb() to
free wide buffers of all files, including legacy standard files that
are small statically allocated objects that do not have wide buffers
and the _mode member.
Fix this by skipping _IO_wsetb() invocation for legacy standard files.
[BZ #24228]
* libio/genops.c (_IO_unbuffer_all)
[SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)]: Skip _IO_wsetb() invocation
for legacy standard files in compatibility mode.
---
ChangeLog | 7 +++++++
libio/genops.c | 7 +++++--
2 files changed, 12 insertions(+), 2 deletions(-)
@@ -816,8 +816,11 @@ _IO_unbuffer_all (void)
_IO_SETBUF (fp, NULL, 0);
- if (fp->_mode > 0)
- _IO_wsetb (fp, NULL, NULL, 0);
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+ if (__glibc_likely (&_IO_stdin_used != NULL) || !_IO_legacy_file (fp))
+#endif
+ if (fp->_mode > 0)
+ _IO_wsetb (fp, NULL, NULL, 0);
#ifdef _IO_MTSAFE_IO
if (cnt < MAXTRIES && fp->_lock != NULL)