warn about time machines; suggested by Thomas Klausner <wiz @ NetBSD>

diff --git a/usr.bin/mandoc/mandoc.1 b/usr.bin/mandoc/mandoc.1
index 1304a3f..d73611d 100644 (file)
--- a/usr.bin/mandoc/mandoc.1
+++ b/usr.bin/mandoc/mandoc.1
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: mandoc.1,v 1.135 2017/07/02 15:31:48 schwarze Exp $
+.\"    $OpenBSD: mandoc.1,v 1.136 2017/07/03 13:40:00 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: July 2 2017 $
+.Dd $Mdocdate: July 3 2017 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
@@ -981,6 +981,14 @@ The date given in a
 or
 .Ic \&TH
 macro does not follow the conventional format.
+.It Sy "date in the future, using it anyway"
+.Pq mdoc , man
+The date given in a
+.Ic \&Dd
+or
+.Ic \&TH
+macro is more than a day ahead of the current system
+.Xr time 3 .
 .It Sy "missing Os macro, using \(dq\(dq"
 .Pq mdoc
 The default or current system is not shown in this case.

diff --git a/usr.bin/mandoc/mandoc.c b/usr.bin/mandoc/mandoc.c
index 3aff3c5..92637e4 100644 (file)
--- a/usr.bin/mandoc/mandoc.c
+++ b/usr.bin/mandoc/mandoc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mandoc.c,v 1.70 2017/06/14 01:31:19 schwarze Exp $ */
+/*     $OpenBSD: mandoc.c,v 1.71 2017/07/03 13:40:00 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -518,6 +518,7 @@ fail:
 char *
 mandoc_normdate(struct roff_man *man, char *in, int ln, int pos)
 {
+       char            *cp;
        time_t           t;
 
        /* No date specified: use today's date. */
@@ -530,13 +531,20 @@ mandoc_normdate(struct roff_man *man, char *in, int ln, int pos)
        /* Valid mdoc(7) date format. */
 
        if (a2time(&t, "$" "Mdocdate: %b %d %Y $", in) ||
-           a2time(&t, "%b %d, %Y", in))
-               return time2a(t);
+           a2time(&t, "%b %d, %Y", in)) {
+               cp = time2a(t);
+               if (t > time(NULL) + 86400)
+                       mandoc_msg(MANDOCERR_DATE_FUTURE, man->parse,
+                           ln, pos, cp);
+               return cp;
+       }
 
        /* In man(7), do not warn about the legacy format. */
 
        if (a2time(&t, "%Y-%m-%d", in) == 0)
                mandoc_msg(MANDOCERR_DATE_BAD, man->parse, ln, pos, in);
+       else if (t > time(NULL) + 86400)
+               mandoc_msg(MANDOCERR_DATE_FUTURE, man->parse, ln, pos, in);
        else if (man->macroset == MACROSET_MDOC)
                mandoc_vmsg(MANDOCERR_DATE_LEGACY, man->parse,
                    ln, pos, "Dd %s", in);

diff --git a/usr.bin/mandoc/mandoc.h b/usr.bin/mandoc/mandoc.h
index a4443df..4fa2e62 100644 (file)
--- a/usr.bin/mandoc/mandoc.h
+++ b/usr.bin/mandoc/mandoc.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mandoc.h,v 1.181 2017/07/02 15:31:48 schwarze Exp $ */
+/*     $OpenBSD: mandoc.h,v 1.182 2017/07/03 13:40:00 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -76,6 +76,7 @@ enum  mandocerr {
        MANDOCERR_MSEC_BAD, /* unknown manual section: Dt ... section */
        MANDOCERR_DATE_MISSING, /* missing date, using today's date */
        MANDOCERR_DATE_BAD, /* cannot parse date, using it verbatim: date */
+       MANDOCERR_DATE_FUTURE, /* date in the future, using it anyway: date */
        MANDOCERR_OS_MISSING, /* missing Os macro, using "" */
        MANDOCERR_PROLOG_REP, /* duplicate prologue macro: macro */
        MANDOCERR_PROLOG_LATE, /* late prologue macro: macro */

diff --git a/usr.bin/mandoc/read.c b/usr.bin/mandoc/read.c
index 5e34172..5c40994 100644 (file)
--- a/usr.bin/mandoc/read.c
+++ b/usr.bin/mandoc/read.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: read.c,v 1.157 2017/07/02 15:31:48 schwarze Exp $ */
+/*     $OpenBSD: read.c,v 1.158 2017/07/03 13:40:00 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -114,6 +114,7 @@ static      const char * const      mandocerrs[MANDOCERR_MAX] = {
        "unknown manual section",
        "missing date, using today's date",
        "cannot parse date, using it verbatim",
+       "date in the future, using it anyway",
        "missing Os macro, using \"\"",
        "duplicate prologue macro",
        "late prologue macro",