Avoid changing file_extra_cnt during deletion.

The I/O code can receive incremental file-list chunks during deletion,
and their OPT_EXTRA fields would get corrupted when file_extra_cnt is
incremented.

Instead of temporarily enabling uid_ndx to find out whether the user
owns a file, have make_file() set a flag for that purpose.

Applied with a few minor tweaks by Wayne.  Fixes bug 7936.

delete.c

@@ -28,7 +28,6 @@ extern int max_delete;
 extern char *backup_dir;
 extern char *backup_suffix;
 extern int backup_suffix_len;
-extern uid_t our_uid;
 extern struct stats stats;
 
 int ignore_perishable = 0;
@@ -98,7 +97,7 @@ static enum delret delete_dir_contents(char *fname, uint16 flags)
 		}
 
 		strlcpy(p, fp->basename, remainder);
-		if (!(fp->mode & S_IWUSR) && !am_root && (uid_t)F_OWNER(fp) == our_uid)
+		if (!(fp->mode & S_IWUSR) && !am_root && fp->flags & FLAG_OWNED_BY_US)
 			do_chmod(fname, fp->mode | S_IWUSR);
 		/* Save stack by recursing to ourself directly. */
 		if (S_ISDIR(fp->mode)) {
@@ -143,19 +142,12 @@ enum delret delete_item(char *fbuf, uint16 mode, uint16 flags)
 		do_chmod(fbuf, mode | S_IWUSR);
 
 	if (S_ISDIR(mode) && !(flags & DEL_DIR_IS_EMPTY)) {
-		int save_uid_ndx = uid_ndx;
 		/* This only happens on the first call to delete_item() since
 		 * delete_dir_contents() always calls us w/DEL_DIR_IS_EMPTY. */
-		if (!uid_ndx)
-			uid_ndx = ++file_extra_cnt;
 		ignore_perishable = 1;
 		/* If DEL_RECURSE is not set, this just reports emptiness. */
 		ret = delete_dir_contents(fbuf, flags);
 		ignore_perishable = 0;
-		if (!save_uid_ndx) {
-			--file_extra_cnt;
-			uid_ndx = 0;
-		}
 		if (ret == DR_NOT_EMPTY || ret == DR_AT_LIMIT)
 			goto check_ret;
 		/* OK: try to delete the directory. */

flist.c

@@ -69,6 +69,7 @@ extern int sender_symlink_iconv;
 extern int output_needs_newline;
 extern int sender_keeps_checksum;
 extern int unsort_ndx;
+extern uid_t our_uid;
 extern struct stats stats;
 extern char *filesfrom_host;
 extern char *usermap, *groupmap;
@@ -1371,10 +1372,12 @@ struct file_struct *make_file(const char *fname, struct file_list *flist,
 	}
 #endif
 	file->mode = st.st_mode;
-	if (uid_ndx) /* Check uid_ndx instead of preserve_uid for del support */
+	if (preserve_uid)
 		F_OWNER(file) = st.st_uid;
-	if (gid_ndx) /* Check gid_ndx instead of preserve_gid for del support */
+	if (preserve_gid)
 		F_GROUP(file) = st.st_gid;
+	if (am_generator && st.st_uid == our_uid)
+		file->flags |= FLAG_OWNED_BY_US;
 
 	if (basename != thisname)
 		file->dirname = lastdir;

generator.c

@@ -276,7 +276,6 @@ static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev)
 	struct file_list *dirlist;
 	char delbuf[MAXPATHLEN];
 	int dlen, i;
-	int save_uid_ndx = uid_ndx;
 
 	if (!fbuf) {
 		change_local_filter_dir(NULL, 0, 0);
@@ -308,9 +307,6 @@ static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev)
 			return;
 	}
 
-	if (!uid_ndx)
-		uid_ndx = ++file_extra_cnt;
-
 	dirlist = get_dirlist(fbuf, dlen, 0);
 
 	/* If an item in dirlist is not found in flist, delete it
@@ -330,7 +326,7 @@ static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev)
 		 * a delete_item call with a DEL_MAKE_ROOM flag. */
 		if (flist_find_ignore_dirness(cur_flist, fp) < 0) {
 			int flags = DEL_RECURSE;
-			if (!(fp->mode & S_IWUSR) && !am_root && (uid_t)F_OWNER(fp) == our_uid)
+			if (!(fp->mode & S_IWUSR) && !am_root && fp->flags & FLAG_OWNED_BY_US)
 				flags |= DEL_NO_UID_WRITE;
 			f_name(fp, delbuf);
 			if (delete_during == 2) {
@@ -342,11 +338,6 @@ static void delete_in_dir(char *fbuf, struct file_struct *file, dev_t *fs_dev)
 	}
 
 	flist_free(dirlist);
-
-	if (!save_uid_ndx) {
-		--file_extra_cnt;
-		uid_ndx = 0;
-	}
 }
 
 /* This deletes any files on the receiving side that are not present on the

rsync.h

@@ -66,6 +66,7 @@
 /* These flags are used in the live flist data. */
 
 #define FLAG_TOP_DIR (1<<0)	/* sender/receiver/generator */
+#define FLAG_OWNED_BY_US (1<<0) /* generator: set by make_file() for aux flists only */
 #define FLAG_FILE_SENT (1<<1)	/* sender/receiver/generator */
 #define FLAG_DIR_CREATED (1<<1)	/* generator */
 #define FLAG_CONTENT_DIR (1<<2)	/* sender/receiver/generator */