sbin/md5.c: fix -q -c for BSD style versions

The BSD style commands (with names not ending in "sum") ignored the -c
options and the passed digest value when invoked with -q.

The man page stated that -q causes only the calculated digest to be
printed, but did not consider the case of both the -q and -c being
used in combination.

Since there is no warning that -c will be ignored when the -q option
is used, users night (and did) expect that the exit code would reflect
the matching of the calculated digest and the argument passed with -c.

This update implements and documents this expected behavior.

PR:		265461
Reported by:	Dmitrij <bugs.freebsd@1fff.net>
MFC after:	2 weeks

(cherry picked from commit 9f3aa538e307743b2b5048d38f87b7fd32d0c596)

2 files changed, 9 insertions, 4 deletions

diff --git a/sbin/md5/md5.1 b/sbin/md5/md5.1
index 899e49ba3517..a3db48596606 100644
--- a/sbin/md5/md5.1
+++ b/sbin/md5/md5.1
@@ -1,5 +1,5 @@
 .\" $FreeBSD$
-.Dd Feb 5, 2022
+.Dd July 26, 2022
 .Dt MD5 1
 .Os
 .Sh NAME
@@ -86,6 +86,9 @@ coreutils versions of these programs.
 If the program was called with a name that does not end in
 .Nm sum ,
 compare the digest of the file against this string.
+If combined with the
+.Fl q
+option, the calculated digest is printed in addition to the exit status being set.
 .Pq Note that this option is not yet useful if multiple files are specified.
 .It Fl c Ar file
 If the program was called with a name that does end in
@@ -94,7 +97,7 @@ the file passed as argument must contain digest lines generated by the same
 digest algorithm with or without the
 .Fl r
 option
-.Pq i.e. in either classical BSD format or in GNU coreutils format .
+.Pq i.e., in either classical BSD format or in GNU coreutils format .
 A line with the file name followed by a colon
 .Dq ":"
 and either OK or FAILED is written for each well-formed line in the digest file.
@@ -164,7 +167,7 @@ d80bf36c332dc0fdc479366ec3fa44cd /etc/rc.conf
 .Pd
 The
 .Nm -sum
-variants put 2 blank characters between hash and file name for full compatibility 
+variants put 2 blank characters between hash and file name for full compatibility
 with the coreutils versions of these commands.
 .Ed
 .Pp
@@ -207,7 +210,7 @@ $ md5 -c digest /boot/loader.conf
 The digest file may contain any number of lines in the format generated with or without the
 .Fl r
 option
-.Pq i.e. in either classical BSD format or in GNU coreutils format .
+.Pq i.e., in either classical BSD format or in GNU coreutils format .
 If a hash value does not match the file, FAILED is printed instead of OK.
 .Sh SEE ALSO
 .Xr cksum 1 ,
diff --git a/sbin/md5/md5.c b/sbin/md5/md5.c
index 7235e6e0a39f..97c587efd63c 100644
--- a/sbin/md5/md5.c
+++ b/sbin/md5/md5.c
@@ -436,6 +436,8 @@ MDOutput(const Algorithm_t *alg, char *p, char *argv[])
 				printf("%s: %s\n", *argv, checkfailed ? "FAILED" : "OK");
 		} else if (qflag || argv == NULL) {
 			printf("%s\n", p);
+			if (cflag)
+				checkfailed = strcasecmp(checkAgainst, p) != 0;
 		} else {
 			if (rflag)
 				if (gnu_emu)