From 1745c06559d8564dfa0b18bc024934cd37855d73 Mon Sep 17 00:00:00 2001 From: nate Date: Sat, 5 Nov 1994 18:49:34 +0000 Subject: Date: Wed, 26 Oct 1994 15:44:49 -0600 From: Chris Torek Here is a semi-official patch (apply to /usr/src/lib/libc/stdio/fseek.c, rebuild libc, install). The current code fails when the seek: - is optimized, and - is to just past the end of the block currently in the buffer, and - is followed by another seek with no intervening read operation, and - the destination of subsequent seek is within the block left in the buffer (seeking to the beginning of a block does not force a read, so the buffer still contains the previous block) so it is indeed rather obscure. I may have a different `final' fix, as this one `loses' the buffer contents on a seek that goes just past the end of the current block. [Footnote: seeks are optimized only on read-only opens of regular files that are buffered by the file's optimal I/O size. This is what you get with fopen(path, "r") and no call to setvbuf().] Obtained from: [ BSDI mailing list ] --- lib/libc/stdio/fseek.c | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/libc') diff --git a/lib/libc/stdio/fseek.c b/lib/libc/stdio/fseek.c index 6b0cc8b..9cb04ad 100644 --- a/lib/libc/stdio/fseek.c +++ b/lib/libc/stdio/fseek.c @@ -213,6 +213,7 @@ fseek(fp, offset, whence) if ((*seekfn)(fp->_cookie, curoff, SEEK_SET) == POS_ERR) goto dumb; fp->_r = 0; + fp->_p = fp->_bf._base; if (HASUB(fp)) FREEUB(fp); fp->_flags &= ~__SEOF; -- cgit v1.1