[epiphany] Set Accept-Language header correctly

[Josselin Mouette <jmouette src gnome org>]

commit 626d441f7aae39c0da5881b1ed2f9e7f3411e9da
Author: Josselin Mouette <joss debian org>
Date:   Mon Aug 16 18:44:42 2010 +0200

    Set Accept-Language header correctly
    
    This makes language autodetection, as implemented by some websites, to
    work.
    
    Most of the code stolen from libsoup.
    Original patch from Mario Sánchez Prada.
    Updated to work with non-English locales.
    Approved by Gustavo Noronha.
    
    Bug 602547

 embed/ephy-embed-prefs.c |   52 ++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 48 insertions(+), 4 deletions(-)
---
diff --git a/embed/ephy-embed-prefs.c b/embed/ephy-embed-prefs.c
index 125cdde..b39238b 100644
--- a/embed/ephy-embed-prefs.c
+++ b/embed/ephy-embed-prefs.c
@@ -278,6 +278,49 @@ webkit_pref_callback_font_family (GConfClient *client,
   }
 }
 
+/* Part of this code taken from libsoup (soup-session.c) */
+static gchar *
+build_accept_languages_header (GArray *languages)
+{
+  gchar **langs = NULL;
+  gchar *langs_str = NULL;
+  gint delta;
+  gint i;
+
+  g_return_val_if_fail (languages != NULL, NULL);
+
+  /* Calculate deltas for the quality values */
+  if (languages->len < 10)
+    delta = 10;
+  else if (languages->len < 20)
+    delta = 5;
+  else
+    delta = 1;
+
+  /* Set quality values for each language */
+  langs = (gchar **) languages->data;
+  for (i = 0; langs[i] != NULL; i++) {
+    gchar *lang = (gchar *) langs[i];
+    gint quality = 100 - i * delta;
+
+    if (quality > 0 && quality < 100) {
+      gchar buf[8];
+      g_ascii_formatd (buf, 8, "%.2f", quality/100.0);
+      langs[i] = g_strdup_printf ("%s;q=%s", lang, buf);
+    } else {
+      /* Just dup the string in this case */
+      langs[i] = g_strdup (lang);
+    }
+    g_free (lang);
+  }
+
+  /* Get the result string */
+  if (languages->len > 0)
+    langs_str = g_strjoinv (", ", langs);
+
+  return langs_str;
+}
+
 /* Based on Christian Persch's code from gecko backend of epiphany
    (old transform_accept_languages_list() function) */
 static void
@@ -290,7 +333,7 @@ webkit_pref_callback_accept_languages (GConfClient *client,
   GConfValue *gcvalue;
   GArray *array;
   GSList *languages, *l;
-  char **langs;
+  char **array_data;
   char *langs_str;
   char *webkit_pref;
 
@@ -318,14 +361,15 @@ webkit_pref_callback_accept_languages (GConfClient *client,
 
   ephy_langs_sanitise (array);
 
-  langs = (char **) g_array_free (array, FALSE);
-  langs_str = g_strjoinv (", ", langs);
+  langs_str = build_accept_languages_header (array);
 
   /* Update Soup session */
   session = webkit_get_default_session ();
   g_object_set (G_OBJECT (session), webkit_pref, langs_str, NULL);
 
-  g_strfreev (langs);
+  /* Free memory */
+  array_data = (char **) g_array_free (array, FALSE);
+  g_strfreev (array_data);
   g_free (langs_str);
 }