From 7820a26ea52032d0330456ae02d4044b357144de Mon Sep 17 00:00:00 2001
From: Ingo Schwarze <schwarze@openbsd.org>
Date: Wed, 15 Mar 2017 10:17:29 +0000
Subject: It's annoying that people keep writing URIs including redundant parts
 like "/OpenBSD-current/manN/".  To discourage that, let man.cgi(8) redirect
 search form results to nice, concise URIs.

---
 cgi.c     | 28 +++++++++++++++++++++++++---
 man.cgi.3 | 24 +++++++++++++++++++++---
 2 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/cgi.c b/cgi.c
index af56da27..05a861d4 100644
--- a/cgi.c
+++ b/cgi.c
@@ -1,4 +1,4 @@
-/*	$Id: cgi.c,v 1.148 2017/02/22 16:20:01 schwarze Exp $ */
+/*	$Id: cgi.c,v 1.149 2017/03/15 10:17:29 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014, 2015, 2016, 2017 Ingo Schwarze <schwarze@usta.de>
@@ -76,6 +76,7 @@ static	void		 pg_error_badrequest(const char *);
 static	void		 pg_error_internal(void);
 static	void		 pg_index(const struct req *);
 static	void		 pg_noresult(const struct req *, const char *);
+static	void		 pg_redirect(const struct req *, const char *);
 static	void		 pg_search(const struct req *);
 static	void		 pg_searchres(const struct req *,
 				struct manpage *, size_t);
@@ -539,6 +540,23 @@ pg_error_internal(void)
 	resp_end_html();
 }
 
+static void
+pg_redirect(const struct req *req, const char *name)
+{
+	printf("Status: 303 See Other\r\n");
+	printf("Location: http://%s/", HTTP_HOST);
+	if (*scriptname != '\0')
+		printf("%s/", scriptname);
+	if (strcmp(req->q.manpath, req->p[0]))
+		printf("%s/", req->q.manpath);
+	if (req->q.arch != NULL)
+		printf("%s/", req->q.arch);
+	printf("%s", name);
+	if (req->q.sec != NULL)
+		printf(".%s", req->q.sec);
+	printf("\r\nContent-Type: text/html; charset=utf-8\r\n\r\n");
+}
+
 static void
 pg_searchres(const struct req *req, struct manpage *r, size_t sz)
 {
@@ -956,9 +974,13 @@ pg_search(const struct req *req)
 		}
 	}
 
-	if (0 == mansearch(&search, &paths, argc, argv, &res, &ressz))
+	res = NULL;
+	ressz = 0;
+	if (req->isquery && req->q.equal && argc == 1)
+		pg_redirect(req, argv[0]);
+	else if (mansearch(&search, &paths, argc, argv, &res, &ressz) == 0)
 		pg_noresult(req, "You entered an invalid query.");
-	else if (0 == ressz)
+	else if (ressz == 0)
 		pg_noresult(req, "No results found.");
 	else
 		pg_searchres(req, res, ressz);
diff --git a/man.cgi.3 b/man.cgi.3
index e7c1d2fc..472d4119 100644
--- a/man.cgi.3
+++ b/man.cgi.3
@@ -1,4 +1,4 @@
-.\"	$Id: man.cgi.3,v 1.2 2016/07/07 19:19:01 schwarze Exp $
+.\"	$Id: man.cgi.3,v 1.3 2017/03/15 10:17:29 schwarze Exp $
 .\"
 .\" Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" 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 2016 $
+.Dd $Mdocdate: March 15 2017 $
 .Dt MAN.CGI 3
 .Os
 .Sh NAME
@@ -126,12 +126,30 @@ contains a search query in short format or when
 is empty and a
 .Ev QUERY_STRING
 is provided.
-It changes into the manpath and calls
+If possible, requests using
+.Ev QUERY_STRING
+are redirected to URIs using
+.Ev PATH_INFO
+by calling
+.Fn pg_redirect .
+Otherwise, it changes into the manpath and calls
 .Xr mansearch 3 .
 Depending on the result, it calls either
 .Fn pg_noresult
 or
 .Fn pg_searchres .
+.It Ft void Fn pg_redirect "const struct req *req" "const char *name"
+This function is special in so far as it does not print an HTML page,
+but only an HTTP 303 response with a Location: of the form:
+.Sm off
+.No http://
+.Ar host Ns /
+.Op Ar scriptname Ns /
+.Op Ar manpath Ns /
+.Op Ar arch Ns /
+.Fa name
+.Op Pf . Ar sec
+.Sm on
 .It Ft void Fn pg_noresult "const struct req *req" "const char *msg"
 This function calls
 .Fn resp_begin_html ,
-- 
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