From 5fe4a96f81734a61d2d5b538ec319f1884412c58 Mon Sep 17 00:00:00 2001
From: claudio <claudio@openbsd.org>
Date: Wed, 27 Dec 2023 17:22:25 +0000
Subject: [PATCH] Fix handling of skipped elements on the very first element
 transmitted. rsync compares e.g. the first mtime against 0, if the mtime is
 the epoch then rsync will skip this field and openrsync will choke when
 receiving it. So if there is no first element but a FLIST_XYZ_SAME flag is
 use 0 as value. Problem noticed by job@ OK tb@ job@ and yoda@ for fixing the
 if statements

---
 usr.bin/rsync/flist.c | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/usr.bin/rsync/flist.c b/usr.bin/rsync/flist.c
index 2b79f341098..cdc9f1da1dd 100644
--- a/usr.bin/rsync/flist.c
+++ b/usr.bin/rsync/flist.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: flist.c,v 1.37 2022/12/26 19:16:02 jmc Exp $ */
+/*	$OpenBSD: flist.c,v 1.38 2023/12/27 17:22:25 claudio Exp $ */
 /*
  * Copyright (c) 2019 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2019 Florian Obser <florian@openbsd.org>
@@ -442,7 +442,7 @@ flist_recv_name(struct sess *sess, int fd, struct flist *f, uint8_t flags,
 	 * than byte-size.
 	 */
 
-	if (FLIST_NAME_SAME & flags) {
+	if (flags & FLIST_NAME_SAME) {
 		if (!io_read_byte(sess, fd, &bval)) {
 			ERRX1("io_read_byte");
 			return 0;
@@ -452,7 +452,7 @@ flist_recv_name(struct sess *sess, int fd, struct flist *f, uint8_t flags,
 
 	/* Get the (possibly-remaining) filename length. */
 
-	if (FLIST_NAME_LONG & flags) {
+	if (flags & FLIST_NAME_LONG) {
 		if (!io_read_size(sess, fd, &pathlen)) {
 			ERRX1("io_read_size");
 			return 0;
@@ -479,7 +479,7 @@ flist_recv_name(struct sess *sess, int fd, struct flist *f, uint8_t flags,
 	}
 	f->path[len] = '\0';
 
-	if (FLIST_NAME_SAME & flags)
+	if (flags & FLIST_NAME_SAME)
 		memcpy(f->path, last, partial);
 
 	if (!io_read_buf(sess, fd, f->path + partial, pathlen)) {
@@ -633,44 +633,41 @@ flist_recv(struct sess *sess, int fd, struct flist **flp, size_t *sz)
 
 		/* Read the modification time. */
 
-		if (!(FLIST_TIME_SAME & flag)) {
+		if (!(flag & FLIST_TIME_SAME)) {
 			if (!io_read_uint(sess, fd, &uival)) {
 				ERRX1("io_read_uint");
 				goto out;
 			}
 			ff->st.mtime = uival;	/* beyond 2038 */
 		} else if (fflast == NULL) {
-			ERRX("same time without last entry");
-			goto out;
+			ff->st.mtime = 0;
 		}  else
 			ff->st.mtime = fflast->st.mtime;
 
 		/* Read the file mode. */
 
-		if (!(FLIST_MODE_SAME & flag)) {
+		if (!(flag & FLIST_MODE_SAME)) {
 			if (!io_read_uint(sess, fd, &uival)) {
 				ERRX1("io_read_uint");
 				goto out;
 			}
 			ff->st.mode = uival;
 		} else if (fflast == NULL) {
-			ERRX("same mode without last entry");
-			goto out;
+			ff->st.mode = 0;
 		} else
 			ff->st.mode = fflast->st.mode;
 
 		/* Conditional part: uid. */
 
 		if (sess->opts->preserve_uids) {
-			if (!(FLIST_UID_SAME & flag)) {
+			if (!(flag & FLIST_UID_SAME)) {
 				if (!io_read_uint(sess, fd, &uival)) {
 					ERRX1("io_read_int");
 					goto out;
 				}
 				ff->st.uid = uival;
 			} else if (fflast == NULL) {
-				ERRX("same uid without last entry");
-				goto out;
+				ff->st.uid = 0;
 			} else
 				ff->st.uid = fflast->st.uid;
 		}
@@ -678,15 +675,14 @@ flist_recv(struct sess *sess, int fd, struct flist **flp, size_t *sz)
 		/* Conditional part: gid. */
 
 		if (sess->opts->preserve_gids) {
-			if (!(FLIST_GID_SAME & flag)) {
+			if (!(flag & FLIST_GID_SAME)) {
 				if (!io_read_uint(sess, fd, &uival)) {
 					ERRX1("io_read_uint");
 					goto out;
 				}
 				ff->st.gid = uival;
 			} else if (fflast == NULL) {
-				ERRX("same gid without last entry");
-				goto out;
+				ff->st.gid = 0;
 			} else
 				ff->st.gid = fflast->st.gid;
 		}
@@ -697,15 +693,14 @@ flist_recv(struct sess *sess, int fd, struct flist **flp, size_t *sz)
 		    S_ISCHR(ff->st.mode))) ||
 		    (sess->opts->specials && (S_ISFIFO(ff->st.mode) ||
 		    S_ISSOCK(ff->st.mode)))) {
-			if (!(FLIST_RDEV_SAME & flag)) {
+			if (!(flag & FLIST_RDEV_SAME)) {
 				if (!io_read_int(sess, fd, &ival)) {
 					ERRX1("io_read_int");
 					goto out;
 				}
 				ff->st.rdev = ival;
 			} else if (fflast == NULL) {
-				ERRX("same device without last entry");
-				goto out;
+				ff->st.rdev = 0;
 			} else
 				ff->st.rdev = fflast->st.rdev;
 		}
-- 
2.20.1