Upstream: fixed X-Accel-Redirect handling from cache files. The X-Accel-Redirect header might appear in cache files if its handling is ignored with the "proxy_ignore_headers" directive. If the cache file is later served with different settings, ngx_http_upstream_process_headers() used to call ngx_http_upstream_finalize_request(NGX_DECLINED), which is not expected to happen before the cleanup handler is installed and resulted in ngx_http_finalize_request(NGX_DONE) (after 5994:5abf5af257a7, nginx 1.7.11), leading to unexpected request counter decrement, "request count is zero" alerts, and segmentation faults. Similarly, errors in ngx_http_upstream_process_headers() resulted in ngx_http_upstream_finalize_request(NGX_HTTP_INTERNAL_SERVER_ERROR) being called. This is also not expected to happen before the cleanup handler is installed, and resulted in ngx_http_finalize_request(NGX_DONE) without proper request finalization. Fix is to avoid calling ngx_http_upstream_finalize_request() from ngx_http_upstream_process_headers(), notably when the cleanup handler is not yet installed. Errors are now simply return NGX_ERROR, so the caller is responsible for proper finalization by calling either ngx_http_finalize_request() or ngx_http_upstream_finalize_request(). And X-Accel-Redirect handling now does not call ngx_http_upstream_finalize_request(NGX_DECLINED) if no cleanup handler is installed. Reported by Jiří Setnička (https://mailman.nginx.org/pipermail/nginx-devel/2024-February/HWLYHOO3DDB3XTFT6X3GRMXIEJ3SJRUA.html).

VER=	$(shell grep 'define NGINX_VERSION' src/core/nginx.h		\
		| sed -e 's/^.*"\(.*\)".*/\1/')
NGINX=	freenginx-$(VER)
TEMP=	tmp
XSLS?=	xslscript.pl


all:		changes

changes:	$(TEMP)/$(NGINX)/CHANGES.ru				\
		$(TEMP)/$(NGINX)/CHANGES


$(TEMP)/$(NGINX)/CHANGES.ru:	docs/dtd/changes.dtd			\
				docs/xml/nginx/changes.xml		\
				docs/xml/change_log_conf.xml		\
				docs/xslt/changes.xslt

	mkdir -p $(TEMP)/$(NGINX)

	xmllint --noout --valid docs/xml/nginx/changes.xml
	xsltproc --stringparam lang ru					\
		-o $@ docs/xslt/changes.xslt docs/xml/nginx/changes.xml


$(TEMP)/$(NGINX)/CHANGES:	docs/dtd/changes.dtd			\
				docs/xml/nginx/changes.xml		\
				docs/xml/change_log_conf.xml		\
				docs/xslt/changes.xslt

	mkdir -p $(TEMP)/$(NGINX)

	xmllint --noout --valid docs/xml/nginx/changes.xml
	xsltproc --stringparam lang en					\
		-o $@ docs/xslt/changes.xslt docs/xml/nginx/changes.xml


docs/xslt/changes.xslt:		docs/xsls/changes.xsls

	$(XSLS) -o $@ $<