Eric Blake wrote:
> > Order of operations. I'm glad to know I'm not the only one that makes this
> > mistake.
>
> Actually, I found the real problem, with a bit more looking at the code.
> With
> this patch, test-fpurge passes on cygwin
Thanks for these fixes. Sorry, I was in a hurry, and don't have a Cygwin
system for testing.
> It also lacks the HASUB/FREEUB macro usage present in the MacOS version of
> fpurge, which means you may have introduced a memory leak.
Indeed. It is quite rare, since pushing back more than 1 byte or pushing back
a byte that was not previously read from the stream is not covered by ISO C 99
(as far as I understand; in particular Solaris and mingw don't support it), but
you are right that if the stream is in that state, fpurge() should do something
sensible.
2007-04-23 Bruno Haible <[EMAIL PROTECTED]>
* lib/fpurge.c (fpurge) [glibc, BSD]: Free a malloc()ed ungetc buffer.
Reported by Eric Blake.
*** lib/fpurge.c 16 Apr 2007 15:02:36 -0000 1.2
--- lib/fpurge.c 23 Apr 2007 08:42:51 -0000
***************
*** 29,34 ****
--- 29,40 ----
#if defined _IO_ferror_unlocked /* GNU libc, BeOS */
fp->_IO_read_end = fp->_IO_read_ptr;
fp->_IO_write_ptr = fp->_IO_write_base;
+ /* Avoid memory leak when there is an active ungetc buffer. */
+ if (fp->_IO_save_base != NULL)
+ {
+ free (fp->_IO_save_base);
+ fp->_IO_save_base = NULL;
+ }
return 0;
#elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X,
Cygwin */
fp->_p = fp->_bf._base;
***************
*** 36,41 ****
--- 42,61 ----
fp->_w = ((fp->_flags & (__SLBF | __SNBF)) == 0 /* fully buffered? */
? fp->_bf._size
: 0);
+ /* Avoid memory leak when there is an active ungetc buffer. */
+ # if defined __NetBSD__ || defined __OpenBSD__ /* NetBSD, OpenBSD */
+ /* See
<http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
+ and
<http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
*/
+ # define fp_ub ((struct { struct __sbuf _ub; } *) fp->_ext._base)->_ub
+ # else /* FreeBSD, MacOS X, Cygwin */
+ # define fp_ub fp->_ub
+ # endif
+ if (fp_ub._base != NULL)
+ {
+ if (fp_ub._base != fp->_ubuf)
+ free (fp_ub._base);
+ fp_ub._base = NULL;
+ }
return 0;
#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris,
mingw */
fp->_ptr = fp->_base;
***************
*** 43,48 ****
fp->_cnt = 0;
return 0;
#else
! #error "Please port gnulib fpurge.c to your platform!"
#endif
}
--- 63,68 ----
fp->_cnt = 0;
return 0;
#else
! #error "Please port gnulib fpurge.c to your platform! Look at the
definitions of fflush, setvbuf and ungetc on your system, then report this to
bug-gnulib."
#endif
}
