new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,25 @@
+/* 
+ * Copyright (C) 2002-2009 Igor Sysoev
+ * Copyright (C) 2009 Maxim Dounin
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */

new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,31 @@
+Gunzip module for nginx.
+
+This module allows ungzipping responses returned with Content-Encoding: gzip
+for clients that doesn't support it.  It may be usefull if you prefer to store
+data compressed (to save space or disk/network IO) but do not want to penalize
+clients without gzip support.
+
+Configuration directives:
+
+    gunzip (on|off)
+
+        Context: http, server, location
+        Default: off
+
+        Switches gunzip.
+
+    gunzip_buffers <number> <size>
+
+        Context: http, server, location
+        Default: 32 4k/16 8k
+
+        Specifies number and size of buffers available for decompression.
+
+Usage:
+
+    location /storage/ {
+        gunzip on;
+    }
+
+To compile nginx with gunzip module, use "--add-module <path>" option to nginx
+configure.

new file mode 100644
--- /dev/null
+++ b/config
@@ -0,0 +1,10 @@
+# (C) Maxim Dounin
+# Configuration for ngx_http_gunzip_filter_module.
+
+ngx_addon_name="ngx_http_gunzip_filter_module"
+
+HTTP_AUX_FILTER_MODULES="$HTTP_AUX_FILTER_MODULES \
+		ngx_http_gunzip_filter_module"
+
+NGX_ADDON_SRCS="$NGX_ADDON_SRCS \
+		$ngx_addon_dir/ngx_http_gunzip_filter_module.c"

new file mode 100644
--- /dev/null
+++ b/ngx_http_gunzip_filter_module.c
@@ -0,0 +1,689 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Maxim Dounin
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+#include <nginx.h>
+
+#include <zlib.h>
+
+
+typedef struct {
+    ngx_flag_t           enable;
+    ngx_bufs_t           bufs;
+} ngx_http_gunzip_conf_t;
+
+
+typedef struct {
+    ngx_chain_t         *in;
+    ngx_chain_t         *free;
+    ngx_chain_t         *busy;
+    ngx_chain_t         *out;
+    ngx_chain_t        **last_out;
+
+    ngx_buf_t           *in_buf;
+    ngx_buf_t           *out_buf;
+    ngx_int_t            bufs;
+
+    unsigned             started:1;
+    unsigned             flush:4;
+    unsigned             redo:1;
+    unsigned             done:1;
+    unsigned             nomem:1;
+
+    z_stream             zstream;
+    ngx_http_request_t  *request;
+} ngx_http_gunzip_ctx_t;
+
+
+static ngx_int_t ngx_http_gunzip_filter_inflate_start(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx);
+static ngx_int_t ngx_http_gunzip_filter_add_data(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx);
+static ngx_int_t ngx_http_gunzip_filter_get_buf(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx);
+static ngx_int_t ngx_http_gunzip_filter_inflate(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx);
+static ngx_int_t ngx_http_gunzip_filter_inflate_end(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx);
+
+static void *ngx_http_gunzip_filter_alloc(void *opaque, u_int items,
+    u_int size);
+static void ngx_http_gunzip_filter_free(void *opaque, void *address);
+
+static ngx_int_t ngx_http_gunzip_filter_init(ngx_conf_t *cf);
+static void *ngx_http_gunzip_create_conf(ngx_conf_t *cf);
+static char *ngx_http_gunzip_merge_conf(ngx_conf_t *cf,
+    void *parent, void *child);
+
+
+static ngx_command_t  ngx_http_gunzip_filter_commands[] = {
+
+    { ngx_string("gunzip"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_gunzip_conf_t, enable),
+      NULL },
+
+    { ngx_string("gunzip_buffers"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
+      ngx_conf_set_bufs_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_gunzip_conf_t, bufs),
+      NULL },
+
+      ngx_null_command
+};
+
+
+static ngx_http_module_t  ngx_http_gunzip_filter_module_ctx = {
+    NULL,                                  /* preconfiguration */
+    ngx_http_gunzip_filter_init,           /* postconfiguration */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    NULL,                                  /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    ngx_http_gunzip_create_conf,           /* create location configuration */
+    ngx_http_gunzip_merge_conf             /* merge location configuration */
+};
+
+
+ngx_module_t  ngx_http_gunzip_filter_module = {
+    NGX_MODULE_V1,
+    &ngx_http_gunzip_filter_module_ctx,    /* module context */
+    ngx_http_gunzip_filter_commands,       /* module directives */
+    NGX_HTTP_MODULE,                       /* module type */
+    NULL,                                  /* init master */
+    NULL,                                  /* init module */
+    NULL,                                  /* init process */
+    NULL,                                  /* init thread */
+    NULL,                                  /* exit thread */
+    NULL,                                  /* exit process */
+    NULL,                                  /* exit master */
+    NGX_MODULE_V1_PADDING
+};
+
+
+static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
+static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;
+
+
+static ngx_int_t
+ngx_http_gunzip_header_filter(ngx_http_request_t *r)
+{
+    ngx_http_gunzip_ctx_t   *ctx;
+    ngx_http_gunzip_conf_t  *conf;
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_gunzip_filter_module);
+
+    /* TODO support multiple content-codings */
+
+    if (!conf->enable
+        || r->headers_out.content_encoding == NULL
+        || r->headers_out.content_encoding->value.len != 4
+        || ngx_strncasecmp(r->headers_out.content_encoding->value.data,
+                           (u_char *) "gzip", 4) != 0)
+    {
+        return ngx_http_next_header_filter(r);
+    }
+
+#if (nginx_version >= 8025)
+
+    r->gzip_vary = 1;
+
+    if (!r->gzip_tested) {
+        if (ngx_http_gzip_ok(r) == NGX_OK) {
+            return ngx_http_next_header_filter(r);
+        }
+
+    } else if (!r->gzip_ok) {
+        return ngx_http_next_header_filter(r);
+    }
+
+#else
+
+    if (ngx_http_gzip_ok(r) == NGX_OK) {
+        return ngx_http_next_header_filter(r);
+    }
+
+#endif
+
+    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_gunzip_ctx_t));
+    if (ctx == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_http_set_ctx(r, ctx, ngx_http_gunzip_filter_module);
+
+    ctx->request = r;
+
+    r->filter_need_in_memory = 1;
+
+    r->headers_out.content_encoding->hash = 0;
+    r->headers_out.content_encoding = NULL;
+
+    ngx_http_clear_content_length(r);
+    ngx_http_clear_accept_ranges(r);
+
+    return ngx_http_next_header_filter(r);
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
+{
+    int                     rc;
+    ngx_chain_t            *cl;
+    ngx_http_gunzip_ctx_t  *ctx;
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_gunzip_filter_module);
+
+    if (ctx == NULL || ctx->done) {
+        return ngx_http_next_body_filter(r, in);
+    }
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "http gunzip filter");
+
+    if (!ctx->started) {
+        if (ngx_http_gunzip_filter_inflate_start(r, ctx) != NGX_OK) {
+            goto failed;
+        }
+    }
+
+    if (in) {
+        if (ngx_chain_add_copy(r->pool, &ctx->in, in) != NGX_OK) {
+            goto failed;
+        }
+    }
+
+    if (ctx->nomem) {
+
+        /* flush busy buffers */
+
+        if (ngx_http_next_body_filter(r, NULL) == NGX_ERROR) {
+            goto failed;
+        }
+
+        cl = NULL;
+
+        ngx_chain_update_chains(&ctx->free, &ctx->busy, &cl,
+                                (ngx_buf_tag_t) &ngx_http_gunzip_filter_module);
+        ctx->nomem = 0;
+    }
+
+    for ( ;; ) {
+
+        /* cycle while we can write to a client */
+
+        for ( ;; ) {
+
+            /* cycle while there is data to feed zlib and ... */
+
+            rc = ngx_http_gunzip_filter_add_data(r, ctx);
+
+            if (rc == NGX_DECLINED) {
+                break;
+            }
+
+            if (rc == NGX_AGAIN) {
+                continue;
+            }
+
+
+            /* ... there are buffers to write zlib output */
+
+            rc = ngx_http_gunzip_filter_get_buf(r, ctx);
+
+            if (rc == NGX_DECLINED) {
+                break;
+            }
+
+            if (rc == NGX_ERROR) {
+                goto failed;
+            }
+
+            rc = ngx_http_gunzip_filter_inflate(r, ctx);
+
+            if (rc == NGX_OK) {
+                break;
+            }
+
+            if (rc == NGX_ERROR) {
+                goto failed;
+            }
+
+            /* rc == NGX_AGAIN */
+        }
+
+        if (ctx->out == NULL) {
+            return ctx->busy ? NGX_AGAIN : NGX_OK;
+        }
+
+        rc = ngx_http_next_body_filter(r, ctx->out);
+
+        if (rc == NGX_ERROR) {
+            goto failed;
+        }
+
+        ngx_chain_update_chains(&ctx->free, &ctx->busy, &ctx->out,
+                                (ngx_buf_tag_t) &ngx_http_gunzip_filter_module);
+        ctx->last_out = &ctx->out;
+
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                       "gunzip out: %p", ctx->out);
+
+        ctx->nomem = 0;
+
+        if (ctx->done) {
+            return rc;
+        }
+    }
+
+    /* unreachable */
+
+failed:
+
+    ctx->done = 1;
+
+    return NGX_ERROR;
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_filter_inflate_start(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx)
+{
+    int  rc;
+
+    ctx->zstream.next_in = Z_NULL;
+    ctx->zstream.avail_in = 0;
+
+    ctx->zstream.zalloc = ngx_http_gunzip_filter_alloc;
+    ctx->zstream.zfree = ngx_http_gunzip_filter_free;
+    ctx->zstream.opaque = ctx;
+
+    /* windowBits +16 to decode gzip, zlib 1.2.0.4+ */
+    rc = inflateInit2(&ctx->zstream, MAX_WBITS + 16);
+
+    if (rc != Z_OK) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "inflateInit2() failed: %d", rc);
+        return NGX_ERROR;
+    }
+
+    ctx->started = 1;
+
+    ctx->last_out = &ctx->out;
+    ctx->flush = Z_NO_FLUSH;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_filter_add_data(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx)
+{
+    if (ctx->zstream.avail_in || ctx->flush != Z_NO_FLUSH || ctx->redo) {
+        return NGX_OK;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "gunzip in: %p", ctx->in);
+
+    if (ctx->in == NULL) {
+        return NGX_DECLINED;
+    }
+
+    ctx->in_buf = ctx->in->buf;
+    ctx->in = ctx->in->next;
+
+    ctx->zstream.next_in = ctx->in_buf->pos;
+    ctx->zstream.avail_in = ctx->in_buf->last - ctx->in_buf->pos;
+
+    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "gunzip in_buf:%p ni:%p ai:%ud",
+                   ctx->in_buf,
+                   ctx->zstream.next_in, ctx->zstream.avail_in);
+
+    if (ctx->in_buf->last_buf || ctx->in_buf->last_in_chain) {
+        ctx->flush = Z_FINISH;
+
+    } else if (ctx->in_buf->flush) {
+        ctx->flush = Z_SYNC_FLUSH;
+
+    } else if (ctx->zstream.avail_in == 0) {
+        /* ctx->flush == Z_NO_FLUSH */
+        return NGX_AGAIN;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_filter_get_buf(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx)
+{
+    ngx_http_gunzip_conf_t  *conf;
+
+    if (ctx->zstream.avail_out) {
+        return NGX_OK;
+    }
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_gunzip_filter_module);
+
+    if (ctx->free) {
+        ctx->out_buf = ctx->free->buf;
+        ctx->free = ctx->free->next;
+
+        ctx->out_buf->flush = 0;
+
+    } else if (ctx->bufs < conf->bufs.num) {
+
+        ctx->out_buf = ngx_create_temp_buf(r->pool, conf->bufs.size);
+        if (ctx->out_buf == NULL) {
+            return NGX_ERROR;
+        }
+
+        ctx->out_buf->tag = (ngx_buf_tag_t) &ngx_http_gunzip_filter_module;
+        ctx->out_buf->recycled = 1;
+        ctx->bufs++;
+
+    } else {
+        ctx->nomem = 1;
+        return NGX_DECLINED;
+    }
+
+    ctx->zstream.next_out = ctx->out_buf->pos;
+    ctx->zstream.avail_out = conf->bufs.size;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_filter_inflate(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx)
+{
+    int           rc;
+    ngx_buf_t    *b;
+    ngx_chain_t  *cl;
+
+    ngx_log_debug6(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "inflate in: ni:%p no:%p ai:%ud ao:%ud fl:%d redo:%d",
+                   ctx->zstream.next_in, ctx->zstream.next_out,
+                   ctx->zstream.avail_in, ctx->zstream.avail_out,
+                   ctx->flush, ctx->redo);
+
+    rc = inflate(&ctx->zstream, ctx->flush);
+
+    if (rc != Z_OK && rc != Z_STREAM_END && rc != Z_BUF_ERROR) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "inflate() failed: %d, %d", ctx->flush, rc);
+        return NGX_ERROR;
+    }
+
+    ngx_log_debug5(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "inflate out: ni:%p no:%p ai:%ud ao:%ud rc:%d",
+                   ctx->zstream.next_in, ctx->zstream.next_out,
+                   ctx->zstream.avail_in, ctx->zstream.avail_out,
+                   rc);
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "gunzip in_buf:%p pos:%p",
+                   ctx->in_buf, ctx->in_buf->pos);
+
+    if (ctx->zstream.next_in) {
+        ctx->in_buf->pos = ctx->zstream.next_in;
+
+        if (ctx->zstream.avail_in == 0) {
+            ctx->zstream.next_in = NULL;
+        }
+    }
+
+    ctx->out_buf->last = ctx->zstream.next_out;
+
+    if (ctx->zstream.avail_out == 0) {
+
+        /* zlib wants to output some more data */
+
+        cl = ngx_alloc_chain_link(r->pool);
+        if (cl == NULL) {
+            return NGX_ERROR;
+        }
+
+        cl->buf = ctx->out_buf;
+        cl->next = NULL;
+        *ctx->last_out = cl;
+        ctx->last_out = &cl->next;
+
+        ctx->redo = 1;
+
+        return NGX_AGAIN;
+    }
+
+    ctx->redo = 0;
+
+    if (ctx->flush == Z_SYNC_FLUSH) {
+
+        ctx->flush = Z_NO_FLUSH;
+
+        cl = ngx_alloc_chain_link(r->pool);
+        if (cl == NULL) {
+            return NGX_ERROR;
+        }
+
+        b = ctx->out_buf;
+
+        if (ngx_buf_size(b) == 0) {
+
+            b = ngx_calloc_buf(ctx->request->pool);
+            if (b == NULL) {
+                return NGX_ERROR;
+            }
+
+        } else {
+            ctx->zstream.avail_out = 0;
+        }
+
+        b->flush = 1;
+
+        cl->buf = b;
+        cl->next = NULL;
+        *ctx->last_out = cl;
+        ctx->last_out = &cl->next;
+
+        return NGX_OK;
+    }
+
+    if (rc == Z_STREAM_END && ctx->flush == Z_FINISH
+        && ctx->zstream.avail_in == 0)
+    {
+
+        if (ngx_http_gunzip_filter_inflate_end(r, ctx) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        return NGX_OK;
+    }
+
+    if (rc == Z_STREAM_END && ctx->zstream.avail_in > 0) {
+
+        rc = inflateReset(&ctx->zstream);
+
+        if (rc != Z_OK) {
+            ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                          "inflateReset() failed: %d", rc);
+            return NGX_ERROR;
+        }
+
+        ctx->redo = 1;
+
+        return NGX_AGAIN;
+    }
+
+    if (ctx->in == NULL) {
+
+        cl = ngx_alloc_chain_link(r->pool);
+        if (cl == NULL) {
+            return NGX_ERROR;
+        }
+
+        b = ctx->out_buf;
+
+        if (ngx_buf_size(b) == 0) {
+
+            b = ngx_calloc_buf(ctx->request->pool);
+            if (b == NULL) {
+                return NGX_ERROR;
+            }
+
+        } else {
+            ctx->zstream.avail_out = 0;
+        }
+
+        cl->buf = b;
+        cl->next = NULL;
+        *ctx->last_out = cl;
+        ctx->last_out = &cl->next;
+
+        return NGX_OK;
+    }
+
+    return NGX_AGAIN;
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_filter_inflate_end(ngx_http_request_t *r,
+    ngx_http_gunzip_ctx_t *ctx)
+{
+    int           rc;
+    ngx_buf_t    *b;
+    ngx_chain_t  *cl;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "gunzip inflate end");
+
+    rc = inflateEnd(&ctx->zstream);
+
+    if (rc != Z_OK) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "inflateEnd() failed: %d", rc);
+        return NGX_ERROR;
+    }
+
+    b = ctx->out_buf;
+
+    if (ngx_buf_size(b) == 0) {
+
+        b = ngx_calloc_buf(ctx->request->pool);
+        if (b == NULL) {
+            return NGX_ERROR;
+        }
+    }
+
+    cl = ngx_alloc_chain_link(r->pool);
+    if (cl == NULL) {
+        return NGX_ERROR;
+    }
+
+    cl->buf = b;
+    cl->next = NULL;
+    *ctx->last_out = cl;
+    ctx->last_out = &cl->next;
+
+    b->last_buf = (r == r->main) ? 1 : 0;
+    b->last_in_chain = 1;
+    b->sync = 1;
+
+    ctx->done = 1;
+
+    return NGX_OK;
+}
+
+
+static void *
+ngx_http_gunzip_filter_alloc(void *opaque, u_int items, u_int size)
+{
+    ngx_http_gunzip_ctx_t *ctx = opaque;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, ctx->request->connection->log, 0,
+                   "gunzip alloc: n:%ud s:%ud",
+                   items, size);
+
+    return ngx_palloc(ctx->request->pool, items * size);
+}
+
+
+static void
+ngx_http_gunzip_filter_free(void *opaque, void *address)
+{
+#if 0
+    ngx_http_gunzip_ctx_t *ctx = opaque;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, ctx->request->connection->log, 0,
+                   "gunzip free: %p", address);
+#endif
+}
+
+
+static void *
+ngx_http_gunzip_create_conf(ngx_conf_t *cf)
+{
+    ngx_http_gunzip_conf_t  *conf;
+
+    conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_gunzip_conf_t));
+    if (conf == NULL) {
+        return NULL;
+    }
+
+    /*
+     * set by ngx_pcalloc():
+     *
+     *     conf->bufs.num = 0;
+     */
+
+    conf->enable = NGX_CONF_UNSET;
+
+    return conf;
+}
+
+
+static char *
+ngx_http_gunzip_merge_conf(ngx_conf_t *cf, void *parent, void *child)
+{
+    ngx_http_gunzip_conf_t *prev = parent;
+    ngx_http_gunzip_conf_t *conf = child;
+
+    ngx_conf_merge_value(conf->enable, prev->enable, 0);
+
+    ngx_conf_merge_bufs_value(conf->bufs, prev->bufs,
+                              (128 * 1024) / ngx_pagesize, ngx_pagesize);
+
+    return NGX_CONF_OK;
+}
+
+
+static ngx_int_t
+ngx_http_gunzip_filter_init(ngx_conf_t *cf)
+{
+    ngx_http_next_header_filter = ngx_http_top_header_filter;
+    ngx_http_top_header_filter = ngx_http_gunzip_header_filter;
+
+    ngx_http_next_body_filter = ngx_http_top_body_filter;
+    ngx_http_top_body_filter = ngx_http_gunzip_body_filter;
+
+    return NGX_OK;
+}

new file mode 100644
--- /dev/null
+++ b/t/gunzip.t
@@ -0,0 +1,101 @@
+#!/usr/bin/perl
+
+# (C) Maxim Dounin
+
+# Tests for gunzip filter module.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+eval { require IO::Compress::Gzip; };
+Test::More::plan(skip_all => "IO::Compress::Gzip not found") if $@;
+
+my $t = Test::Nginx->new()->has('--with-http_gzip_static_module')->plan(10);
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+master_process off;
+daemon         off;
+
+events {
+}
+
+http {
+    access_log    off;
+    root          %%TESTDIR%%;
+
+    client_body_temp_path  %%TESTDIR%%/client_body_temp;
+    fastcgi_temp_path      %%TESTDIR%%/fastcgi_temp;
+    proxy_temp_path        %%TESTDIR%%/proxy_temp;
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+        location / {
+            gunzip on;
+            gzip_vary on;
+            proxy_pass http://127.0.0.1:8081/;
+            proxy_set_header Accept-Encoding gzip;
+        }
+        location /error {
+            error_page 500 /t1;
+            return 500;
+        }
+    }
+
+    server {
+        listen       127.0.0.1:8081;
+        server_name  localhost;
+
+        location / {
+            default_type text/plain;
+            gzip_static on;
+            gzip_http_version 1.0;
+            gzip_types text/plain;
+        }
+    }
+}
+
+EOF
+
+my $in = join('', map { sprintf "X%03dXXXXXX", $_ } (0 .. 99));
+my $out;
+
+IO::Compress::Gzip::gzip(\$in => \$out);
+
+$t->write_file('t1.gz', $out);
+$t->write_file('t2.gz', $out . $out);
+$t->write_file('t3', 'not compressed');
+
+$t->run();
+
+###############################################################################
+
+pass('runs');
+
+my $t1 = http_get('/t1');
+unlike($t1, qr/Content-Encoding/, 'no content encoding');
+like($t1, qr/^(X\d\d\dXXXXXX){100}$/m, 'correct ungzipped response');
+
+like(http_get('/t2'), qr/^(X\d\d\dXXXXXX){200}$/m, 'multiple gzip members');
+
+like(http_get('/error'), qr/^(X\d\d\dXXXXXX){100}$/m, 'errors ungzipped');
+
+unlike(http_head('/t1'), qr/Content-Encoding/, 'head - no content encoding');
+
+like(http_get('/t1'), qr/Vary/, 'get vary');
+like(http_head('/t1'), qr/Vary/, 'head vary');
+unlike(http_get('/t3'), qr/Vary/, 'no vary on non-gzipped get');
+unlike(http_head('/t3'), qr/Vary/, 'no vary on non-gzipped head');
+
+###############################################################################