new file mode 100644
--- /dev/null
+++ b/fastcgi_extra_data.t
@@ -0,0 +1,192 @@
+#!/usr/bin/perl
+
+# (C) Maxim Dounin
+# (C) Nginx, Inc.
+
+# Test for fastcgi backend, responses with extra data or premature close.
+
+###############################################################################
+
+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;
+
+eval { require FCGI; };
+plan(skip_all => 'FCGI not installed') if $@;
+plan(skip_all => 'win32') if $^O eq 'MSWin32';
+
+my $t = Test::Nginx->new()
+	->has(qw/http fastcgi cache rewrite addition/)->plan(20)
+	->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    fastcgi_param REQUEST_URI $request_uri;
+    fastcgi_param REQUEST_METHOD $request_method;
+
+    fastcgi_cache_path cache keys_zone=one:1m;
+    fastcgi_cache_key $request_uri;
+    fastcgi_cache_valid any 1m;
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location / {
+            fastcgi_pass 127.0.0.1:8081;
+            add_after_body /after;
+        }
+
+        location /unbuf/ {
+            fastcgi_pass 127.0.0.1:8081;
+            fastcgi_buffering off;
+            add_after_body /after;
+        }
+
+        location /head/ {
+            fastcgi_pass 127.0.0.1:8081;
+            fastcgi_cache one;
+            add_after_body /after;
+        }
+
+        location /after {
+            return 200 ":after\n";
+        }
+    }
+}
+
+EOF
+
+$t->run_daemon(\&fastcgi_daemon);
+$t->run()->waitforsocket('127.0.0.1:' . port(8081));
+
+###############################################################################
+
+TODO: {
+local $TODO = 'not yet' unless $t->has_version('1.19.1');
+
+like(http_get('/'), qr/SEE-THIS(?!-BUT-NOT-THIS)/, 'response with extra data');
+like(http_get('/short'), qr/SEE-THIS(?!.*:after)/s, 'too short response');
+like(http_get('/empty'), qr/200 OK(?!.*:after)/s, 'empty too short response');
+
+}
+
+like(http_head('/'), qr/200 OK(?!.*SEE-THIS)/s, 'no data in HEAD');
+like(http_head('/short'), qr/200 OK(?!.*SEE-THIS)/s, 'too short to HEAD');
+like(http_head('/empty'), qr/200 OK/, 'empty response to HEAD');
+
+# unbuffered responses
+
+TODO: {
+local $TODO = 'not yet' unless $t->has_version('1.19.1');
+
+like(http_get('/unbuf/'), qr/SEE-THIS(?!-BUT-NOT-THIS)/,
+	'unbuffered with extra data');
+like(http_get('/unbuf/short'), qr/SEE-THIS(?!.*:after)/s,
+	'unbuffered too short response');
+like(http_get('/unbuf/empty'), qr/200 OK(?!.*:after)/s,
+	'unbuffered empty too short responsde');
+
+}
+
+like(http_head('/unbuf/'), qr/200 OK(?!.*SEE-THIS)/s,
+	'unbuffered no data in HEAD');
+like(http_head('/unbuf/short'), qr/200 OK(?!.*SEE-THIS)/s,
+	'unbuffered too short response to HEAD');
+like(http_head('/unbuf/empty'), qr/200 OK/,
+	'unbuffered empty response to HEAD');
+
+# caching of responsses to HEAD requests
+
+like(http_head('/head/empty'), qr/200 OK(?!.*SEE-THIS)/s, 'head no body');
+like(http_head('/head/matching'), qr/200 OK(?!.*SEE-THIS)/s, 'head matching');
+like(http_head('/head/extra'), qr/200 OK(?!.*SEE-THIS)/s, 'head extra');
+like(http_head('/head/short'), qr/200 OK(?!.*SEE-THIS)/s, 'head too short');
+
+like(http_get('/head/empty'), qr/200 OK/, 'head no body cached');
+like(http_get('/head/matching'), qr/SEE-THIS/, 'head matching cached');
+
+TODO: {
+local $TODO = 'not yet' unless $t->has_version('1.19.1');
+
+like(http_get('/head/extra'), qr/SEE-THIS(?!-BUT-NOT-THIS)/s,
+	'head extra cached');
+like(http_get('/head/short'), qr/SEE-THIS(?!.*:after)/s,
+	'head too short cached');
+
+}
+
+###############################################################################
+
+sub fastcgi_daemon {
+	my $socket = FCGI::OpenSocket('127.0.0.1:' . port(8081), 5);
+	my $request = FCGI::Request(\*STDIN, \*STDOUT, \*STDERR, \%ENV,
+		$socket);
+
+	my ($uri, $head);
+
+	while( $request->Accept() >= 0 ) {
+		$uri = $ENV{REQUEST_URI};
+		$uri =~ s!^/unbuf!!;
+
+		$head = $ENV{REQUEST_METHOD} eq 'HEAD';
+
+		if ($uri eq '/') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 8\n\n";
+			print "SEE-THIS-BUT-NOT-THIS\n";
+
+		} elsif ($uri eq '/short') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 100\n\n";
+			print "SEE-THIS-TOO-SHORT-RESPONSE\n";
+
+		} elsif ($uri eq '/empty') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 100\n\n";
+
+		} elsif ($uri eq '/head/empty') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 8\n\n";
+			print "SEE-THIS" unless $head;
+
+		} elsif ($uri eq '/head/matching') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 8\n\n";
+			print "SEE-THIS";
+
+		} elsif ($uri eq '/head/extra') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 8\n\n";
+			print "SEE-THIS-BUT-NOT-THIS\n";
+
+		} elsif ($uri eq '/head/short') {
+			print "Content-Type: text/html\n";
+			print "Content-Length: 100\n\n";
+			print "SEE-THIS\n";
+		}
+	}
+
+	FCGI::CloseSocket($socket);
+}
+
+###############################################################################