about: always ensure page has a trailing slash

Otherwise we can't easily embed links to other /about/ pages.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

cgit.c

@@ -742,6 +742,9 @@ static void process_request(void)
 	if (ctx.repo && prepare_repo_cmd())
 		return;
 
+	if (cmd->pre)
+		cmd->pre();
+
 	if (cmd->want_layout) {
 		cgit_print_http_headers();
 		cgit_print_docstart();

cmd.c

@@ -44,6 +44,12 @@ static void about_fn(void)
 		cgit_print_site_readme();
 }
 
+static void about_pre(void)
+{
+	if (ctx.repo && !ctx.qry.path && ctx.qry.url[strlen(ctx.qry.url) - 1] != '/')
+		cgit_redirect(fmtalloc("%s/", cgit_currenturl()), true);
+}
+
 static void blob_fn(void)
 {
 	cgit_print_blob(ctx.qry.sha1, ctx.qry.path, ctx.qry.head, 0);
@@ -136,15 +142,17 @@ static void tree_fn(void)
 	cgit_print_tree(ctx.qry.sha1, ctx.qry.path);
 }
 
+#define def_cmp(name, want_repo, want_layout, want_vpath, is_clone) \
+	{#name, name##_fn, name##_pre, want_repo, want_layout, want_vpath, is_clone}
 #define def_cmd(name, want_repo, want_layout, want_vpath, is_clone) \
-	{#name, name##_fn, want_repo, want_layout, want_vpath, is_clone}
+	{#name, name##_fn, NULL, want_repo, want_layout, want_vpath, is_clone}
 
 struct cgit_cmd *cgit_get_cmd(void)
 {
 	static struct cgit_cmd cmds[] = {
 		def_cmd(HEAD, 1, 0, 0, 1),
 		def_cmd(atom, 1, 0, 0, 0),
-		def_cmd(about, 0, 1, 0, 0),
+		def_cmp(about, 0, 1, 0, 0),
 		def_cmd(blob, 1, 0, 0, 0),
 		def_cmd(commit, 1, 1, 1, 0),
 		def_cmd(diff, 1, 1, 1, 0),

cmd.h

@@ -2,10 +2,12 @@
 #define CMD_H
 
 typedef void (*cgit_cmd_fn)(void);
+typedef void (*cgit_cmd_pre_fn)(void);
 
 struct cgit_cmd {
 	const char *name;
 	cgit_cmd_fn fn;
+	cgit_cmd_pre_fn pre;
 	unsigned int want_repo:1,
 		want_layout:1,
 		want_vpath:1,

ui-shared.c

@@ -689,6 +689,14 @@ void cgit_print_http_headers(void)
 		exit(0);
 }
 
+void cgit_redirect(const char *url, bool permanent)
+{
+	htmlf("Status: %d %s\n", permanent ? 301 : 302, permanent ? "Moved" : "Found");
+	htmlf("Location: %s\n", url);
+	htmlf("\n");
+	exit(0);
+}
+
 static void print_rel_vcs_link(const char *url)
 {
 	html("<link rel='vcs-git' href='");

ui-shared.h

@@ -1,6 +1,8 @@
 #ifndef UI_SHARED_H
 #define UI_SHARED_H
 
+#include <stdbool.h>
+
 extern const char *cgit_httpscheme();
 extern const char *cgit_hosturl();
 extern const char *cgit_rooturl();
@@ -61,6 +63,7 @@ extern void cgit_vprint_error(const char *fmt, va_list ap);
 extern void cgit_print_date(time_t secs, const char *format, int local_time);
 extern void cgit_print_age(time_t t, time_t max_relative, const char *format);
 extern void cgit_print_http_headers(void);
+extern void cgit_redirect(const char *url, bool permanent);
 extern void cgit_print_docstart(void);
 extern void cgit_print_docend();
 extern void cgit_print_pageheader(void);