upstream: Pass "ControlMaster no" to ssh when invoked by scp & sftp.

If you have ControlMaster auto (or yes) in your config, and the
first connection you make is via scp or sftp, then you may get a
few unexpected options applied to it (eg ForwardX11 no), since sftp
and sftp explicitly disable those for reasons.  These effects will
persist beyond the initial scp or sftp command.

This explicitly disables persistent session *creation* by scp and sftp.
It will not prevent them from using an existing session if one has
already been created.

From Github PR#557, ok djm@ kn@

OpenBSD-Commit-ID: 9dad7c737466837e0150c4318920f46d844770c4

Author: daztucker

scp.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: scp.c,v 1.262 2025/03/19 06:11:15 dtucker Exp $ */
+/* $OpenBSD: scp.c,v 1.263 2025/03/28 06:04:07 dtucker Exp $ */
 /*
  * scp - secure remote copy.  This is basically patched BSD rcp which
  * uses ssh to do the data transfer (instead of using rcmd).
@@ -505,6 +505,7 @@ main(int argc, char **argv)
 	addargs(&args, "-oClearAllForwardings=yes");
 	addargs(&args, "-oRemoteCommand=none");
 	addargs(&args, "-oRequestTTY=no");
+	addargs(&args, "-oControlMaster=no");
 
 	fflag = Tflag = tflag = 0;
 	while ((ch = getopt(argc, argv,

sftp.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.239 2024/06/26 23:14:14 deraadt Exp $ */
+/* $OpenBSD: sftp.c,v 1.240 2025/03/28 06:04:07 dtucker Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <[email protected]>
  *
@@ -2463,6 +2463,7 @@ main(int argc, char **argv)
 	addargs(&args, "-oForwardX11 no");
 	addargs(&args, "-oPermitLocalCommand no");
 	addargs(&args, "-oClearAllForwardings yes");
+	addargs(&args, "-oControlMaster no");
 
 	ll = SYSLOG_LEVEL_INFO;
 	infile = stdin;