new file mode 100644
--- /dev/null
+++ b/debug_connection.t
@@ -0,0 +1,91 @@
+#!/usr/bin/perl
+
+# (C) Nginx, Inc
+
+# Tests for debug_connection.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->has(qw/http --with-debug ipv6 proxy/);
+
+plan(skip_all => 'not yet') unless $t->has_version('1.5.2');
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+    debug_connection ::1;
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    error_log %%TESTDIR%%/debug1.log alert;
+    error_log %%TESTDIR%%/debug2.log alert;
+
+    server {
+        listen       127.0.0.1:8080;
+        listen       [::1]:8080;
+        server_name  localhost;
+
+        location /debug {
+            proxy_pass http://[::1]:8080/;
+        }
+    }
+}
+
+EOF
+
+eval {
+	open OLDERR, ">&", \*STDERR; close STDERR;
+	$t->run();
+	open STDERR, ">&", \*OLDERR;
+};
+plan(skip_all => 'no inet6 support') if $@;
+
+$t->plan(5);
+
+###############################################################################
+
+my $d = $t->testdir();
+
+http_get('/');
+is(read_file("$d/debug1.log"), '', 'no debug_connection file 1');
+is(read_file("$d/debug2.log"), '', 'no debug_connection file 1');
+
+http_get('/debug');
+like(read_file("$d/debug1.log"), qr/\[debug\]/, 'debug_connection file 1');
+like(read_file("$d/debug2.log"), qr/\[debug\]/, 'debug_connection file 2');
+is(read_file("$d/debug1.log"), read_file("$d/debug2.log"),
+	'debug_connection file1 file2 match');
+
+###############################################################################
+
+sub read_file {
+	my ($file) = shift;
+	open my $fh, '<', $file or return "$!";
+	local $/;
+	my $content = <$fh>;
+	close $fh;
+	return $content;
+}
+
+###############################################################################