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From: tlaronde@polynum.com
To: ori@eigenstate.org
Cc: 9front@9front.org
Subject: Re: [FOUND] [9front] putc/fputc incorrect return
Date: Sat, 11 Jul 2020 16:39:22 +0200	[thread overview]
Message-ID: <20200711143922.GB563@polynum.com> (raw)
In-Reply-To: <9886E456A839F5CDF03974A2426A0518@eigenstate.org>

Here is the simple code exhibiting the problem. There are three
components:

1) int is negative;
2) there are at least two successive calls;
3) the stream is neither stdout nor stderr.

#include <u.h>
#include <stdio.h>

int
main(int argc, char *argv[])
{
	FILE *fp;
	short w;

	if ( (fp = fopen("/tmp/bug.tfm", "wb")) == NULL ) {
		(void)fprintf(stderr, "Unable to open '/tmp/bug.tfm' for writing.\n");
		return 1;
	}

	/* Writing successively negative word on the file stream: bug.
	 */
	w = 0xffaa;
	(void)fprintf(stderr, "\nWriting big endian '%#hx' on file stream returned"
		" -> %#x %#x\n", w, putc(w >> 8, fp), putc(w, fp));

	/* On stdout, no problem.
	 */
	(void)fprintf(stderr, "\nWriting big endian '%#hx' on stdout returned"
		" -> %#x %#x\n", w, putc(w >> 8, stdout), putc(w, stdout));

	return 0;
}

Best,
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                     http://www.kergis.com/
                       http://www.sbfa.fr/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89  250D 52B1 AE95 6006 F40C


  reply	other threads:[~2020-07-11 14:39 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-09  8:21 putc/fputc incorrect return? tlaronde
2020-07-09 14:27 ` [9front] " ori
2020-07-09 16:17   ` tlaronde
2020-07-09 16:55     ` ori
2020-07-09 18:29       ` tlaronde
2020-07-09 18:39         ` ori
2020-07-11 14:39           ` tlaronde [this message]
2020-07-11 15:45             ` [FOUND] [9front] putc/fputc incorrect return ori
2020-07-11 16:43               ` tlaronde
2020-07-13 10:36               ` tlaronde

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