http: add Accept-Language header if possible
authorYi EungJun <eungjun.yi@navercorp.com>
Wed, 28 Jan 2015 12:04:37 +0000 (21:04 +0900)
committerJunio C Hamano <gitster@pobox.com>
Wed, 28 Jan 2015 19:17:08 +0000 (11:17 -0800)
Add an Accept-Language header which indicates the user's preferred
languages defined by $LANGUAGE, $LC_ALL, $LC_MESSAGES and $LANG.

Examples:
  LANGUAGE= -> ""
  LANGUAGE=ko:en -> "Accept-Language: ko, en;q=0.9, *;q=0.1"
  LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *;q=0.1"
  LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *;q=0.1"

This gives git servers a chance to display remote error messages in
the user's preferred language.

Limit the number of languages to 1,000 because q-value must not be
smaller than 0.001, and limit the length of Accept-Language header to
4,000 bytes for some HTTP servers which cannot accept such long header.

Signed-off-by: Yi EungJun <eungjun.yi@navercorp.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http.c
remote-curl.c
t/t5550-http-fetch-dumb.sh

diff --git a/http.c b/http.c
index 040f362..8b659b6 100644 (file)
--- a/http.c
+++ b/http.c
@@ -68,6 +68,8 @@ static struct curl_slist *no_pragma_header;
 
 static struct active_request_slot *active_queue_head;
 
+static char *cached_accept_language;
+
 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 {
        size_t size = eltsize * nmemb;
@@ -515,6 +517,9 @@ void http_cleanup(void)
                cert_auth.password = NULL;
        }
        ssl_cert_password_required = 0;
+
+       free(cached_accept_language);
+       cached_accept_language = NULL;
 }
 
 struct active_request_slot *get_active_slot(void)
@@ -986,6 +991,142 @@ static void extract_content_type(struct strbuf *raw, struct strbuf *type,
                strbuf_addstr(charset, "ISO-8859-1");
 }
 
+/*
+ * Guess the user's preferred languages from the value in LANGUAGE environment
+ * variable and LC_MESSAGES locale category if NO_GETTEXT is not defined.
+ *
+ * The result can be a colon-separated list like "ko:ja:en".
+ */
+static const char *get_preferred_languages(void)
+{
+       const char *retval;
+
+       retval = getenv("LANGUAGE");
+       if (retval && *retval)
+               return retval;
+
+#ifndef NO_GETTEXT
+       retval = setlocale(LC_MESSAGES, NULL);
+       if (retval && *retval &&
+               strcmp(retval, "C") &&
+               strcmp(retval, "POSIX"))
+               return retval;
+#endif
+
+       return NULL;
+}
+
+static void write_accept_language(struct strbuf *buf)
+{
+       /*
+        * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
+        * that, q-value will be smaller than 0.001, the minimum q-value the
+        * HTTP specification allows. See
+        * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
+        */
+       const int MAX_DECIMAL_PLACES = 3;
+       const int MAX_LANGUAGE_TAGS = 1000;
+       const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
+       char **language_tags = NULL;
+       int num_langs = 0;
+       const char *s = get_preferred_languages();
+       int i;
+       struct strbuf tag = STRBUF_INIT;
+
+       /* Don't add Accept-Language header if no language is preferred. */
+       if (!s)
+               return;
+
+       /*
+        * Split the colon-separated string of preferred languages into
+        * language_tags array.
+        */
+       do {
+               /* collect language tag */
+               for (; *s && (isalnum(*s) || *s == '_'); s++)
+                       strbuf_addch(&tag, *s == '_' ? '-' : *s);
+
+               /* skip .codeset, @modifier and any other unnecessary parts */
+               while (*s && *s != ':')
+                       s++;
+
+               if (tag.len) {
+                       num_langs++;
+                       REALLOC_ARRAY(language_tags, num_langs);
+                       language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
+                       if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
+                               break;
+               }
+       } while (*s++);
+
+       /* write Accept-Language header into buf */
+       if (num_langs) {
+               int last_buf_len = 0;
+               int max_q;
+               int decimal_places;
+               char q_format[32];
+
+               /* add '*' */
+               REALLOC_ARRAY(language_tags, num_langs + 1);
+               language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
+
+               /* compute decimal_places */
+               for (max_q = 1, decimal_places = 0;
+                    max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
+                    decimal_places++, max_q *= 10)
+                       ;
+
+               sprintf(q_format, ";q=0.%%0%dd", decimal_places);
+
+               strbuf_addstr(buf, "Accept-Language: ");
+
+               for (i = 0; i < num_langs; i++) {
+                       if (i > 0)
+                               strbuf_addstr(buf, ", ");
+
+                       strbuf_addstr(buf, language_tags[i]);
+
+                       if (i > 0)
+                               strbuf_addf(buf, q_format, max_q - i);
+
+                       if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
+                               strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
+                               break;
+                       }
+
+                       last_buf_len = buf->len;
+               }
+       }
+
+       /* free language tags -- last one is a static '*' */
+       for (i = 0; i < num_langs - 1; i++)
+               free(language_tags[i]);
+       free(language_tags);
+}
+
+/*
+ * Get an Accept-Language header which indicates user's preferred languages.
+ *
+ * Examples:
+ *   LANGUAGE= -> ""
+ *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
+ *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
+ *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
+ *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
+ *   LANGUAGE= LANG=C -> ""
+ */
+static const char *get_accept_language(void)
+{
+       if (!cached_accept_language) {
+               struct strbuf buf = STRBUF_INIT;
+               write_accept_language(&buf);
+               if (buf.len > 0)
+                       cached_accept_language = strbuf_detach(&buf, NULL);
+       }
+
+       return cached_accept_language;
+}
+
 /* http_request() targets */
 #define HTTP_REQUEST_STRBUF    0
 #define HTTP_REQUEST_FILE      1
@@ -998,6 +1139,7 @@ static int http_request(const char *url,
        struct slot_results results;
        struct curl_slist *headers = NULL;
        struct strbuf buf = STRBUF_INIT;
+       const char *accept_language;
        int ret;
 
        slot = get_active_slot();
@@ -1023,6 +1165,11 @@ static int http_request(const char *url,
                                         fwrite_buffer);
        }
 
+       accept_language = get_accept_language();
+
+       if (accept_language)
+               headers = curl_slist_append(headers, accept_language);
+
        strbuf_addstr(&buf, "Pragma:");
        if (options && options->no_cache)
                strbuf_addstr(&buf, " no-cache");
index dd63bc2..04989e5 100644 (file)
@@ -962,6 +962,8 @@ int main(int argc, const char **argv)
        struct strbuf buf = STRBUF_INIT;
        int nongit;
 
+       git_setup_gettext();
+
        git_extract_argv0_path(argv[0]);
        setup_git_directory_gently(&nongit);
        if (argc < 2) {
index ac71418..e1e2938 100755 (executable)
@@ -196,5 +196,47 @@ test_expect_success 'reencoding is robust to whitespace oddities' '
        grep "this is the error message" stderr
 '
 
+check_language () {
+       case "$2" in
+       '')
+               >expect
+               ;;
+       ?*)
+               echo "Accept-Language: $1" >expect
+               ;;
+       esac &&
+       GIT_CURL_VERBOSE=1 \
+       LANGUAGE=$2 \
+       git ls-remote "$HTTPD_URL/dumb/repo.git" >output 2>&1 &&
+       tr -d '\015' <output |
+       sort -u |
+       sed -ne '/^Accept-Language:/ p' >actual &&
+       test_cmp expect actual
+}
+
+test_expect_success 'git client sends Accept-Language based on LANGUAGE' '
+       check_language "ko-KR, *;q=0.9" ko_KR.UTF-8'
+
+test_expect_success 'git client sends Accept-Language correctly with unordinary LANGUAGE' '
+       check_language "ko-KR, *;q=0.9" "ko_KR:" &&
+       check_language "ko-KR, en-US;q=0.9, *;q=0.8" "ko_KR::en_US" &&
+       check_language "ko-KR, *;q=0.9" ":::ko_KR" &&
+       check_language "ko-KR, en-US;q=0.9, *;q=0.8" "ko_KR!!:en_US" &&
+       check_language "ko-KR, ja-JP;q=0.9, *;q=0.8" "ko_KR en_US:ja_JP"'
+
+test_expect_success 'git client sends Accept-Language with many preferred languages' '
+       check_language "ko-KR, en-US;q=0.9, fr-CA;q=0.8, de;q=0.7, sr;q=0.6, \
+ja;q=0.5, zh;q=0.4, sv;q=0.3, pt;q=0.2, *;q=0.1" \
+               ko_KR.EUC-KR:en_US.UTF-8:fr_CA:de.UTF-8@euro:sr@latin:ja:zh:sv:pt &&
+       check_language "ko-KR, en-US;q=0.99, fr-CA;q=0.98, de;q=0.97, sr;q=0.96, \
+ja;q=0.95, zh;q=0.94, sv;q=0.93, pt;q=0.92, nb;q=0.91, *;q=0.90" \
+               ko_KR.EUC-KR:en_US.UTF-8:fr_CA:de.UTF-8@euro:sr@latin:ja:zh:sv:pt:nb
+'
+
+test_expect_success 'git client does not send an empty Accept-Language' '
+       GIT_CURL_VERBOSE=1 LANGUAGE= git ls-remote "$HTTPD_URL/dumb/repo.git" 2>stderr &&
+       ! grep "^Accept-Language:" stderr
+'
+
 stop_httpd
 test_done