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-rw-r--r--http.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/http.c b/http.c
index 2cdf67d830..efdab09796 100644
--- a/http.c
+++ b/http.c
@@ -71,6 +71,8 @@ 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;
@@ -549,6 +551,9 @@ 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)
@@ -996,6 +1001,142 @@ static void extract_content_type(struct strbuf *raw, struct strbuf *type,
}
+/*
+ * 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
@@ -1008,6 +1149,7 @@ 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();
@@ -1033,6 +1175,11 @@ 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");