# HG changeset patch
# User Roman Arutyunyan <arut@nginx.com>
# Date 1490986076 -10800
# Node ID 3ff293cfdab85082a9560ab56ea9f16b02a8a8c8
# Parent  a97ad1663ef4e7ef75cbcb9d472b603b21f77e2d
Slice filter: prevented slice redirection (ticket #1219).

When a slice subrequest was redirected to a new location, its context was lost.
After its completion, a new slice subrequest for the same slice was created.
This could lead to infinite loop.  Now the slice module makes sure each slice
subrequest starts output with the slice context available.

diff --git a/src/http/modules/ngx_http_slice_filter_module.c b/src/http/modules/ngx_http_slice_filter_module.c
--- a/src/http/modules/ngx_http_slice_filter_module.c
+++ b/src/http/modules/ngx_http_slice_filter_module.c
@@ -20,7 +20,8 @@ typedef struct {
     off_t                end;
     ngx_str_t            range;
     ngx_str_t            etag;
-    ngx_uint_t           last;  /* unsigned  last:1; */
+    unsigned             last:1;
+    unsigned             active:1;
     ngx_http_request_t  *sr;
 } ngx_http_slice_ctx_t;
 
@@ -170,6 +171,7 @@ ngx_http_slice_header_filter(ngx_http_re
     }
 
     ctx->start = end;
+    ctx->active = 1;
 
     r->headers_out.status = NGX_HTTP_OK;
     r->headers_out.status_line.len = 0;
@@ -238,6 +240,12 @@ ngx_http_slice_body_filter(ngx_http_requ
         return rc;
     }
 
+    if (!ctx->active) {
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "missing slice response");
+        return NGX_ERROR;
+    }
+
     if (ctx->start >= ctx->end) {
         ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module);
         ngx_http_send_special(r, NGX_HTTP_LAST);
@@ -263,6 +271,8 @@ ngx_http_slice_body_filter(ngx_http_requ
                                  ctx->start + (off_t) slcf->size - 1)
                      - ctx->range.data;
 
+    ctx->active = 0;
+
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http slice subrequest: \"%V\"", &ctx->range);