new file mode 100644
--- /dev/null
+++ b/proxy_cache_vary.t
@@ -0,0 +1,266 @@
+#!/usr/bin/perl
+
+# (C) Maxim Dounin
+
+# Tests for http proxy cache, the Vary header.
+
+###############################################################################
+
+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;
+
+plan(skip_all => 'win32') if $^O eq 'MSWin32';
+
+my $t = Test::Nginx->new()->has(qw/http proxy cache gzip rewrite/)
+	->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    proxy_cache_path   %%TESTDIR%%/cache keys_zone=one:1m inactive=5s;
+    proxy_cache_key    $uri;
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        add_header X-Cache-Status $upstream_cache_status;
+
+        location / {
+            proxy_pass    http://127.0.0.1:8081/;
+            proxy_cache   one;
+        }
+
+        location /replace/ {
+            proxy_pass    http://127.0.0.1:8081/;
+            proxy_cache   one;
+        }
+
+        location /revalidate/ {
+            proxy_pass    http://127.0.0.1:8081/;
+            proxy_cache   one;
+            proxy_cache_revalidate on;
+        }
+
+        location /ignore/ {
+            proxy_pass    http://127.0.0.1:8081/;
+            proxy_cache   one;
+            proxy_ignore_headers Vary;
+        }
+    }
+
+    server {
+        listen       127.0.0.1:8081;
+        server_name  localhost;
+
+        gzip on;
+        gzip_min_length 0;
+        gzip_http_version 1.0;
+        gzip_vary on;
+
+        expires 2s;
+
+        location / {
+            if ($args = "novary") {
+                return 200 "the only variant\n";
+            }
+        }
+
+        location /asterisk {
+            gzip off;
+            add_header Vary "*";
+        }
+
+        location /complex {
+            gzip off;
+            add_header Vary ",, Accept-encoding , ,";
+        }
+    }
+}
+
+EOF
+
+$t->write_file('index.html', 'SEE-THIS');
+$t->write_file('asterisk', 'SEE-THIS');
+$t->write_file('complex', 'SEE-THIS');
+
+$t->try_run('no proxy_ignore_headers Vary')->plan(40);
+
+###############################################################################
+
+local $TODO = 'not yet';
+
+like(get('/', 'gzip'), qr/MISS/ms, 'first request');
+like(get('/', 'gzip'), qr/HIT/ms, 'vary match cached');
+like(get('/', 'deflate'), qr/MISS/ms, 'vary mismatch');
+like(get('/', 'deflate'), qr/HIT/ms, 'vary mismatch cached');
+like(get('/', 'foo'), qr/MISS/ms, 'vary mismatch 2');
+like(get('/', 'foo'), qr/HIT/ms, 'vary mismatch 2 cached');
+like(get('/', 'gzip'), qr/HIT/ms, 'multiple representations cached');
+
+SKIP: {
+skip 'long tests', 6 unless $ENV{TEST_NGINX_UNSAFE};
+
+# make sure all variants are properly expire
+# and removed after inactive timeout
+
+sleep(3);
+
+like(get('/', 'gzip'), qr/EXPIRED/ms, 'first expired');
+like(get('/', 'deflate'), qr/EXPIRED/ms, 'second variant expired');
+
+like(get('/', 'gzip'), qr/HIT/ms, 'first cached after expire');
+like(get('/', 'deflate'), qr/HIT/ms, 'second cached after expire');
+
+sleep(12);
+
+like(get('/', 'gzip'), qr/MISS/ms, 'first inactive removed');
+like(get('/', 'deflate'), qr/MISS/ms, 'second variant removed');
+
+}
+
+SKIP: {
+skip 'long tests', 6 unless $ENV{TEST_NGINX_UNSAFE};
+
+# check if the variant which was loaded first will be properly
+# removed if it's not requested (but another variant is requested
+# at the same time)
+
+sleep(3);
+like(get('/', 'deflate'), qr/EXPIRED/ms, 'bump1');
+sleep(3);
+like(get('/', 'deflate'), qr/EXPIRED/ms, 'bump2');
+sleep(3);
+like(get('/', 'deflate'), qr/EXPIRED/ms, 'bump3');
+sleep(3);
+like(get('/', 'deflate'), qr/EXPIRED/ms, 'bump4');
+
+TODO: {
+local $TODO = 'not yet';
+
+like(head('/', 'gzip'), qr/MISS/ms, 'first not bumped by second requests');
+
+}
+
+like(head('/', 'deflate'), qr/HIT/ms, 'second variant cached');
+
+}
+
+# if a response without Vary is returned to replace previously returned
+# responses with Vary, make sure it is then used in all cases
+
+like(get('/replace/', 'gzip'), qr/MISS/, 'replace first');
+like(get('/replace/', 'deflate'), qr/MISS/, 'replace second');
+
+sleep(3);
+
+like(get('/replace/?novary', 'deflate'), qr/EXPIRED/, 'replace novary');
+like(get('/replace/?zztest', 'gzip'), qr/HIT/, 'all replaced');
+
+# make sure revalidation of variants works fine
+
+like(get('/revalidate/', 'gzip'), qr/MISS/, 'revalidate first');
+like(get('/revalidate/', 'deflate'), qr/MISS/, 'revalidate second');
+
+sleep(3);
+
+like(get('/revalidate/', 'gzip'), qr/REVALIDATED/, 'revalidated first');
+like(get('/revalidate/', 'deflate'), qr/REVALIDATED/, 'revalidated second');
+like(get('/revalidate/', 'gzip'), qr/HIT/, 'revalidate first after');
+like(get('/revalidate/', 'deflate'), qr/HIT/, 'revalidate second after');
+
+# if the Vary header is ignored, cached version can be returned
+# regardless of request headers
+
+like(get('/ignore/', 'gzip'), qr/MISS/ms, 'another request');
+like(get('/ignore/', 'deflate'), qr/HIT/ms, 'vary ignored');
+
+# check parsing of Vary with multiple headers listed
+
+like(get('/complex', 'gzip'), qr/MISS/ms, 'vary complex first');
+like(get('/complex', 'deflate'), qr/MISS/ms, 'vary complex second');
+like(get('/complex', 'gzip'), qr/HIT/ms, 'vary complex first cached');
+like(get('/complex', 'deflate'), qr/HIT/ms, 'vary complex second cached');
+
+# From RFC 7231, "7.1.4. Vary",
+# http://tools.ietf.org/html/rfc7231#section-7.1.4:
+#
+#    A Vary field value of "*" signals that anything about the request
+#    might play a role in selecting the response representation, possibly
+#    including elements outside the message syntax (e.g., the client's
+#    network address).  A recipient will not be able to determine whether
+#    this response is appropriate for a later request without forwarding
+#    the request to the origin server.
+#
+# In theory, If-None-Match can be used to check if the representation
+# present in the cache is appropriate.  This seems to be only possible
+# with strong entity tags though, as representation with different
+# content condings may share the same weak entity tag.
+
+like(get('/asterisk', 'gzip'), qr/MISS/ms, 'vary asterisk first');
+like(get('/asterisk', 'gzip'), qr/MISS/ms, 'vary asterisk second');
+
+# From RFC 7234, "4.1. Calculating Secondary Keys with Vary",
+# http://tools.ietf.org/html/rfc7234#section-4.1:
+#
+#    The selecting header fields from two requests are defined to match if
+#    and only if those in the first request can be transformed to those in
+#    the second request by applying any of the following:
+#
+#    o  adding or removing whitespace, where allowed in the header field's
+#       syntax
+# 
+#    o  combining multiple header fields with the same field name (see
+#       Section 3.2 of [RFC7230])
+# 
+#    o  normalizing both header field values in a way that is known to
+#       have identical semantics, according to the header field's
+#       specification (e.g., reordering field values when order is not
+#       significant; case-normalization, where values are defined to be
+#       case-insensitive)
+#
+# No normalization is currently implemented.
+
+like(get('/', 'foo, bar'), qr/MISS/ms, 'normalize first');
+
+TODO: {
+local $TODO = 'not yet';
+
+like(get('/', 'foo,bar'), qr/HIT/ms, 'normalize whitespace');
+like(get('/', 'bar,foo'), qr/HIT/ms, 'normalize order');
+
+}
+
+###############################################################################
+
+sub get {
+	my ($url, $extra) = @_;
+	return http(<<EOF);
+GET $url HTTP/1.1
+Host: localhost
+Connection: close
+Accept-Encoding: $extra
+
+EOF
+}
+
+###############################################################################