[evolution] Show online help when the local is not installed

[Milan Crha <mcrha src gnome org>]

commit f3a6159ca75f896dba6425830d3d55eb18b77641
Author: Milan Crha <mcrha redhat com>
Date:   Fri Mar 13 09:24:55 2015 +0100

    Show online help when the local is not installed
    
    Also fix reference to sections, thus the yelp opens the right
    section, instead of the main window.

 e-util/e-misc-utils.c |   29 +++++++++++++++++++++++++++--
 1 files changed, 27 insertions(+), 2 deletions(-)
---
diff --git a/e-util/e-misc-utils.c b/e-util/e-misc-utils.c
index 173b3f2..c36a965 100644
--- a/e-util/e-misc-utils.c
+++ b/e-util/e-misc-utils.c
@@ -256,6 +256,23 @@ e_show_uri (GtkWindow *parent,
        g_error_free (error);
 }
 
+static gboolean
+e_misc_utils_is_help_package_installed (void)
+{
+       gboolean is_installed;
+       gchar *path;
+
+       /* Viewing user documentation requires the evolution help
+        * files. Look for one of the files it installs. */
+       path = g_build_filename (EVOLUTION_DATADIR, "help", "C", PACKAGE, "index.page", NULL);
+
+       is_installed = g_file_test (path, G_FILE_TEST_IS_REGULAR);
+
+       g_free (path);
+
+       return is_installed;
+}
+
 /**
  * e_display_help:
  * @parent: a parent #GtkWindow or %NULL
@@ -276,14 +293,22 @@ e_display_help (GtkWindow *parent,
        GError *error = NULL;
        guint32 timestamp;
 
-       uri = g_string_new ("help:" PACKAGE);
+       if (e_misc_utils_is_help_package_installed ()) {
+               uri = g_string_new ("help:" PACKAGE);
+       } else {
+               uri = g_string_new ("https://help.gnome.org/users/"; PACKAGE "/");
+               g_string_append_printf (uri, "%d.%d", EDS_MAJOR_VERSION, EDS_MINOR_VERSION);
+       }
+
        timestamp = gtk_get_current_event_time ();
 
        if (parent != NULL)
                screen = gtk_widget_get_screen (GTK_WIDGET (parent));
 
+       g_string_append (uri, "/");
+
        if (link_id != NULL)
-               g_string_append_printf (uri, "?%s", link_id);
+               g_string_append (uri, link_id);
 
        if (gtk_show_uri (screen, uri->str, timestamp, &error))
                goto exit;