bug#23750: 25.0.95; bug in url-retrieve or json.el

[Kentaro NAKAZAWA]

Why can not I use multibyte text for http requests?
The following correct http request will fail.

(require 'json)
(let* ((content "ほげ <- VALID utf-8 Japanese multibyte text")
       (url "https://api.github.com/gists";)
       (url-request-method "POST")
       (url-request-data
        (json-encode
         `(("description" . "test")
           ("public" . false)
           ("files" . (("test.txt" . (("content" . ,content)))))))))
  (with-current-buffer (url-retrieve-synchronously url)
    (buffer-string)))
=> url-http-create-request: Multibyte text in HTTP request: POST /gists
HTTP/1.1

Please apply the following patch.

--- url-http.el.orig    2016-09-15 17:16:04.000000000 +0900
+++ url-http.el 2016-11-29 17:10:57.018703500 +0900
@@ -351,16 +351,12 @@
              (if url-http-data
                  (concat
                   "Content-length: " (number-to-string
-                                      (length url-http-data))
+                                      (string-bytes url-http-data))
                   "\r\n"))
              ;; End request
              "\r\n"
              ;; Any data
              url-http-data))
-    ;; Bug#23750
-    (unless (= (string-bytes request)
-               (length request))
-      (error "Multibyte text in HTTP request: %s" request))
     (url-http-debug "Request is: \n%s" request)
     request))