Support a second argument to -O man,

selecting the format according to local existence of the file.
Suggested by kristaps@ during EuroBSDCon 2018.
Written on the train Frankfurt-Karlsruhe returning from EuroBSDCon.

4 files changed, 31 insertions, 10 deletions

diff --git a/usr.bin/mandoc/html.c b/usr.bin/mandoc/html.c
index 4b758ed130a..0268171bb44 100644
--- a/usr.bin/mandoc/html.c
+++ b/usr.bin/mandoc/html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: html.c,v 1.109 2018/08/16 13:49:40 schwarze Exp $ */
+/*	$OpenBSD: html.c,v 1.110 2018/10/02 12:32:55 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2015, 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -16,6 +16,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 #include <sys/types.h>
+#include <sys/stat.h>
 
 #include <assert.h>
 #include <ctype.h>
@@ -126,7 +127,10 @@ html_alloc(const struct manoutput *outopts)
 
 	h->tag = NULL;
 	h->style = outopts->style;
-	h->base_man = outopts->man;
+	if ((h->base_man1 = outopts->man) == NULL)
+		h->base_man2 = NULL;
+	else if ((h->base_man2 = strchr(h->base_man1, ';')) != NULL)
+		*h->base_man2++ = '\0';
 	h->base_includes = outopts->includes;
 	if (outopts->fragment)
 		h->oflags |= HTML_FRAGMENT;
@@ -465,9 +469,21 @@ print_encode(struct html *h, const char *p, const char *pend, int norecurse)
 static void
 print_href(struct html *h, const char *name, const char *sec, int man)
 {
+	struct stat	 sb;
 	const char	*p, *pp;
+	char		*filename;
+
+	if (man) {
+		pp = h->base_man1;
+		if (h->base_man2 != NULL) {
+			mandoc_asprintf(&filename, "%s.%s", name, sec);
+			if (stat(filename, &sb) == -1)
+				pp = h->base_man2;
+			free(filename);
+		}
+	} else
+		pp = h->base_includes;
 
-	pp = man ? h->base_man : h->base_includes;
 	while ((p = strchr(pp, '%')) != NULL) {
 		print_encode(h, pp, p, 1);
 		if (man && p[1] == 'S') {
diff --git a/usr.bin/mandoc/html.h b/usr.bin/mandoc/html.h
index 750c4b7e095..700eca2bc18 100644
--- a/usr.bin/mandoc/html.h
+++ b/usr.bin/mandoc/html.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: html.h,v 1.54 2018/06/25 16:54:55 schwarze Exp $ */
+/*	$OpenBSD: html.h,v 1.55 2018/10/02 12:32:55 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -101,7 +101,8 @@ struct	html {
 	struct tag	 *tag; /* last open tag */
 	struct rofftbl	  tbl; /* current table */
 	struct tag	 *tblt; /* current open table scope */
-	char		 *base_man; /* base for manpage href */
+	char		 *base_man1; /* bases for manpage href */
+	char		 *base_man2;
 	char		 *base_includes; /* base for include href */
 	char		 *style; /* style-sheet URI */
 	struct tag	 *metaf; /* current open font scope */
diff --git a/usr.bin/mandoc/mandoc.1 b/usr.bin/mandoc/mandoc.1
index aa19c49d634..02d2a00dd6a 100644
--- a/usr.bin/mandoc/mandoc.1
+++ b/usr.bin/mandoc/mandoc.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: mandoc.1,v 1.152 2018/08/25 16:43:52 schwarze Exp $
+.\"	$OpenBSD: mandoc.1,v 1.153 2018/10/02 12:32:55 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2012, 2014-2018 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: August 25 2018 $
+.Dd $Mdocdate: October 2 2018 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
@@ -345,7 +345,7 @@ Instances of
 are replaced with the include filename.
 The default is not to present a
 hyperlink.
-.It Cm man Ns = Ns Ar fmt
+.It Cm man Ns = Ns Ar fmt Ns Op ; Ns Ar fmt
 The string
 .Ar fmt ,
 for example,
@@ -361,6 +361,10 @@ are replaced with the linked manual's name and section, respectively.
 If no section is included, section 1 is assumed.
 The default is not to
 present a hyperlink.
+If two formats are given and a file
+.Ar %N.%S
+exists in the current directory, the first format is used;
+otherwise, the second format is used.
 .It Cm style Ns = Ns Ar style.css
 The file
 .Ar style.css
diff --git a/usr.bin/mandoc/mdoc_html.c b/usr.bin/mandoc/mdoc_html.c
index eab4bd60bf7..7af29f7f2fa 100644
--- a/usr.bin/mandoc/mdoc_html.c
+++ b/usr.bin/mandoc/mdoc_html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mdoc_html.c,v 1.186 2018/08/17 20:31:52 schwarze Exp $ */
+/*	$OpenBSD: mdoc_html.c,v 1.187 2018/10/02 12:32:55 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014,2015,2016,2017,2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -609,7 +609,7 @@ mdoc_xr_pre(MDOC_ARGS)
 	if (NULL == n->child)
 		return 0;
 
-	if (h->base_man)
+	if (h->base_man1)
 		print_otag(h, TAG_A, "cThM", "Xr",
 		    n->child->string, n->child->next == NULL ?
 		    NULL : n->child->next->string);