For -Tlint, put parser messages on stdout instead of stderr.

Originally, naddy@ requested this in 2011 (or maybe even earlier).
It was discussed with joerg@, kristaps@, naddy@, and espie@ in 2011,
and everybody agreed in principle, but it was postponed because
kristaps@ wanted to do some cleanup of the message system first.
Meanwhile, message infrastructure was improved about a dozen times...

This makes long, tedious commands like "mandoc -Tlint *.1 2>&1 | less"
unnecessary and allows simple ones like "man -l -Tlint *.1".

3 files changed, 16 insertions, 20 deletions

diff --git a/TODO b/TODO
index ed71dab0..e23f811b 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,6 @@
 ************************************************************************
 * Official mandoc TODO.
-* $Id: TODO,v 1.242 2017/07/20 12:54:02 schwarze Exp $
+* $Id: TODO,v 1.243 2017/07/20 15:26:41 schwarze Exp $
 ************************************************************************
 
 Many issues are annotated for difficulty as follows:
@@ -436,11 +436,6 @@ are mere guesses, and some may be wrong.
   Probably, this should be fixed somewhere in termp_it_pre(), not sure.
   loc *  exist **  algo **  size *  imp **
 
-- In .Bl -tag, if a tag exceeds the right margin and must be continued
-  on the next line, it must be indented by -width, not width+1;
-  see "rule block|pass" in OpenBSD ifconfig(8).
-  loc *  exist ***  algo **  size *  imp **
-
 - When the -width string contains macros, the macros must be rendered
   before measuring the width, for example
     .Bl -tag -width ".Dv message"
@@ -492,10 +487,6 @@ are mere guesses, and some may be wrong.
   but just the overall format
   loc **  exist **  algo ***  size **  imp **
 
-- -Tlint parser errors and warnings to stdout
-  to tech@mdocml, naddy@  Wed, 28 Sep 2011 11:21:46 +0200
-  wait!  kristaps@  Sun, 02 Oct 2011 17:12:52 +0200
-
 ************************************************************************
 * documentation issues
 ************************************************************************
diff --git a/main.c b/main.c
index ef051e53..8b600bbc 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$Id: main.c,v 1.299 2017/07/04 14:40:38 schwarze Exp $ */
+/*	$Id: main.c,v 1.300 2017/07/20 15:26:41 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -111,6 +111,7 @@ static	const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9};
 static	char		  help_arg[] = "help";
 static	char		 *help_argv[] = {help_arg, NULL};
 static	enum mandoclevel  rc;
+static	FILE		 *mmsg_stream;
 
 
 int
@@ -190,6 +191,7 @@ main(int argc, char *argv[])
 	curp.mmin = MANDOCERR_MAX;
 	curp.outopts = &conf.output;
 	options = MPARSE_SO | MPARSE_UTF8 | MPARSE_LATIN1;
+	mmsg_stream = stderr;
 
 	use_pager = 1;
 	tag_files = NULL;
@@ -994,6 +996,7 @@ toptions(struct curparse *curp, char *arg)
 	else if (0 == strcmp(arg, "lint")) {
 		curp->outtype = OUTT_LINT;
 		curp->mmin = MANDOCERR_BASE;
+		mmsg_stream = stdout;
 	} else if (0 == strcmp(arg, "tree"))
 		curp->outtype = OUTT_TREE;
 	else if (0 == strcmp(arg, "man"))
@@ -1083,21 +1086,21 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 {
 	const char	*mparse_msg;
 
-	fprintf(stderr, "%s: %s:", getprogname(),
+	fprintf(mmsg_stream, "%s: %s:", getprogname(),
 	    file == NULL ? "<stdin>" : file);
 
 	if (line)
-		fprintf(stderr, "%d:%d:", line, col + 1);
+		fprintf(mmsg_stream, "%d:%d:", line, col + 1);
 
-	fprintf(stderr, " %s", mparse_strlevel(lvl));
+	fprintf(mmsg_stream, " %s", mparse_strlevel(lvl));
 
 	if ((mparse_msg = mparse_strerror(t)) != NULL)
-		fprintf(stderr, ": %s", mparse_msg);
+		fprintf(mmsg_stream, ": %s", mparse_msg);
 
 	if (msg)
-		fprintf(stderr, ": %s", msg);
+		fprintf(mmsg_stream, ": %s", msg);
 
-	fputc('\n', stderr);
+	fputc('\n', mmsg_stream);
 }
 
 static pid_t
diff --git a/mandoc.1 b/mandoc.1
index 88ea880f..1db4d325 100644
--- a/mandoc.1
+++ b/mandoc.1
@@ -1,4 +1,4 @@
-.\"	$Id: mandoc.1,v 1.216 2017/07/07 16:20:30 schwarze Exp $
+.\"	$Id: mandoc.1,v 1.217 2017/07/20 15:26:41 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 7 2017 $
+.Dd $Mdocdate: July 20 2017 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
@@ -238,7 +238,9 @@ See
 .It Fl T Cm lint
 Parse only: produce no output.
 Implies
-.Fl W Cm all .
+.Fl W Cm all
+and redirects parser messages, which usually appear
+on standard error output, to standard output.
 .It Fl T Cm locale
 Encode output using the current locale.
 This is the default.