add a comment about sed and suid bits

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/editors/sed.c b/editors/sed.c
index a5ef400fc..28f0c7318 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -1365,6 +1365,8 @@ int sed_main(int argc UNUSED_PARAM, char **argv)
 
                         /* Set permissions/owner of output file */
                         fstat(fileno(file), &statbuf);
+                        /* chmod'ing AFTER chown would preserve suid/sgid bits,
+                         * but GNU sed 4.2.1 does not preserve them either */
                         fchmod(nonstdoutfd, statbuf.st_mode);
                         fchown(nonstdoutfd, statbuf.st_uid, statbuf.st_gid);
                         add_input_file(file);