[gnome-software/wip/ubuntu-xenial] Fix conversion from star ratings (1-5) to G-S rating (0-100)

[Robert Ancell <rancell src gnome org>]

commit dba47823e829850edb8d0f3eafc3d3a139d96c2f
Author: Robert Ancell <robert ancell canonical com>
Date:   Wed Jun 8 12:17:55 2016 +1200

    Fix conversion from star ratings (1-5) to G-S rating (0-100)

 src/plugins/gs-plugin-ubuntu-reviews.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/gs-plugin-ubuntu-reviews.c b/src/plugins/gs-plugin-ubuntu-reviews.c
index a93eb83..79f3556 100644
--- a/src/plugins/gs-plugin-ubuntu-reviews.c
+++ b/src/plugins/gs-plugin-ubuntu-reviews.c
@@ -254,7 +254,7 @@ get_rating (gint64 one_star_count, gint64 two_star_count, gint64 three_star_coun
        return (((wilson_score (one_star_count, n_ratings, 0.1) * -2) +
                 (wilson_score (two_star_count, n_ratings, 0.1) * -1) +
                 (wilson_score (four_star_count, n_ratings, 0.1) * 1) +
-                (wilson_score (five_star_count, n_ratings, 0.1) * 2)) + 3) * 20;
+                (wilson_score (five_star_count, n_ratings, 0.1) * 2)) + 3) * 20 - 10;
 }
 
 static gboolean
@@ -634,7 +634,7 @@ parse_review (GsPlugin *plugin, JsonNode *node)
        gs_review_set_version (review, json_object_get_string_member (object, "version"));
        star_rating = json_object_get_int_member (object, "rating");
        if (star_rating > 0)
-               gs_review_set_rating (review, star_rating * 20);
+               gs_review_set_rating (review, star_rating * 20 - 10);
        gs_review_set_date (review, parse_date_time (json_object_get_string_member (object, "date_created")));
        id_string = g_strdup_printf ("%" G_GINT64_FORMAT, json_object_get_int_member (object, "id"));
        gs_review_add_metadata (review, "ubuntu-id", id_string);