Merge from fonosfera

libs/httpclient/luasrc/httpclient/receiver.lua

@@ -171,8 +171,10 @@ function request_to_file(uri, target, options, cbs)
 	cbs = cbs or {}
 	options.headers = options.headers or {}
 	local hdr = options.headers
+	local file, code, msg
 	
-	local file, code, msg = prepare_fd(target)
+	if target then
+		file, code, msg = prepare_fd(target)
 		if not file then
 			return file, code, msg
 		end
@@ -183,33 +185,48 @@ function request_to_file(uri, target, options, cbs)
 		if off > 0 then
 			hdr.Range = hdr.Range or ("bytes=" .. off .. "-")  
 		end
+	end
 	
 	local code, resp, buffer, sock = httpc.request_raw(uri, options)
 	if not code then
 		-- No success
+		if file then
 			file:close()
+		end
 		return code, resp, buffer
 	elseif hdr.Range and code ~= 206 then
 		-- We wanted a part but we got the while file
 		sock:close()
+		if file then
 			file:close()
+		end
 		return nil, -4, code, resp
 	elseif not hdr.Range and code ~= 200 then
 		-- We encountered an error
 		sock:close()
+		if file then
 			file:close()
+		end
 		return nil, -4, code, resp
 	end
 	
 	if cbs.on_header then
 		local stat = {cbs.on_header(file, code, resp)}
 		if stat[1] == false then
+			if file then
 				file:close()
+			end
 			sock:close()
 			return unpack(stat)
+		elseif stat[2] then
+			file = file and stat[2]
 		end
 	end
 	
+	if not file then
+		return nil, -5, "no target given"
+	end
+
 	local chunked = resp.headers["Transfer-Encoding"] == "chunked"
 	local stat