MFC r301974: ar: enable reproducible output by default when invoked as 'ar -s'

ar output is already deterministic by default for ar -q and ar -r, and
when invoked as ranlib. Make ar -s equivalent to ranlib and enable
deterministic output by default in that case too.

PR:		210330
Sponsored by:	The FreeBSD Foundation

2 files changed, 9 insertions, 3 deletions

diff --git a/usr.bin/ar/ar.1 b/usr.bin/ar/ar.1
index 079d262..ed8266c 100644
--- a/usr.bin/ar/ar.1
+++ b/usr.bin/ar/ar.1
@@ -23,7 +23,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 24, 2015
+.Dd July 25, 2016
 .Dt AR 1
 .Os
 .Sh NAME
@@ -205,7 +205,12 @@ When used in combination with the
 .Fl r
 or
 .Fl q
-option, insert 0's instead of the real mtime, uid and gid values
+option,
+with the
+.Fl s
+option without other options, or when invoked as
+.Nm ranlib ,
+insert 0's instead of the real mtime, uid and gid values
 and 0644 instead of file mode from the members named by arguments
 .Ar .
 This ensures that checksums on the resulting archives are reproducible
diff --git a/usr.bin/ar/ar.c b/usr.bin/ar/ar.c
index 0c69315..0ab06a0 100644
--- a/usr.bin/ar/ar.c
+++ b/usr.bin/ar/ar.c
@@ -283,7 +283,8 @@ main(int argc, char **argv)
 	}
 
 	/* Set determinstic mode for -D, and by default without -U. */
-	if (Dflag || (Uflag == 0 && (bsdar->mode == 'q' || bsdar->mode == 'r')))
+	if (Dflag || (Uflag == 0 && (bsdar->mode == 'q' || bsdar->mode == 'r' ||
+	    (bsdar->mode == '\0' && bsdar->options & AR_S))))
 		bsdar->options |= AR_D;
 
 	if (bsdar->options & AR_A)