Merge of r4275, r4276, r4278, r4279: Fixes for proxy_set_header, fastcgi/scgi/uwsgi_param inheritance: *) Fixed proxy_set_header inheritance with proxy_cache (ticket #45). Headers cleared with cache enabled (If-Modified-Since etc.) might be cleared in unrelated servers/locations without proxy_cache enabled if proxy_cache was used in some server/location. Example config which triggered the problem: proxy_set_header X-Test "test"; server { location /1 { proxy_cache name; proxy_pass ... } } server { location /2 { proxy_pass ... } } Another one: server { proxy_cache name; location /1 { proxy_pass ... } location /2 { proxy_cache off; proxy_pass ... } } In both cases If-Modified-Since header wasn't sent to backend in location /2. Fix is to not modify conf->headers_source, but instead merge user-supplied headers from conf->headers_source and default headers (either cache or not) into separate headers_merged array. *) Fixed proxy_set_header inheritance with proxy_set_body. *) Separate functions to merge fastcgi/scgi/uwsgi params. No functional changes. *) Fixed fastcgi/scgi/uwsgi_param inheritance. The following problems were fixed: 1. Directive fastcgi_cache affected headers sent to backends in unrelated servers / locations (see ticket #45). 2. If-Unmodified-Since, If-Match and If-Range headers were sent to backends if fastcgi_cache was used. 3. Cache-related headers were sent to backends if there were no fastcgi_param directives and fastcgi_cache was used at server level.

/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_LIST_H_INCLUDED_
#define _NGX_LIST_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct ngx_list_part_s  ngx_list_part_t;

struct ngx_list_part_s {
    void             *elts;
    ngx_uint_t        nelts;
    ngx_list_part_t  *next;
};


typedef struct {
    ngx_list_part_t  *last;
    ngx_list_part_t   part;
    size_t            size;
    ngx_uint_t        nalloc;
    ngx_pool_t       *pool;
} ngx_list_t;


ngx_list_t *ngx_list_create(ngx_pool_t *pool, ngx_uint_t n, size_t size);

static ngx_inline ngx_int_t
ngx_list_init(ngx_list_t *list, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{
    list->part.elts = ngx_palloc(pool, n * size);
    if (list->part.elts == NULL) {
        return NGX_ERROR;
    }

    list->part.nelts = 0;
    list->part.next = NULL;
    list->last = &list->part;
    list->size = size;
    list->nalloc = n;
    list->pool = pool;

    return NGX_OK;
}


/*
 *
 *  the iteration through the list:
 *
 *  part = &list.part;
 *  data = part->elts;
 *
 *  for (i = 0 ;; i++) {
 *
 *      if (i >= part->nelts) {
 *          if (part->next == NULL) {
 *              break;
 *          }
 *
 *          part = part->next;
 *          data = part->elts;
 *          i = 0;
 *      }
 *
 *      ...  data[i] ...
 *
 *  }
 */


void *ngx_list_push(ngx_list_t *list);


#endif /* _NGX_LIST_H_INCLUDED_ */