[gnome-software/1228-assertion-crash-under-gs_feature_tile_refresh] gs-feature-tile: Do not abort when the theme is broken

[Milan Crha <mcrha src gnome org>]

commit 3a644c151f27f439c36170f0958fd21cf1cc54d0
Author: Milan Crha <mcrha redhat com>
Date:   Thu Jun 3 08:33:53 2021 +0200

    gs-feature-tile: Do not abort when the theme is broken
    
    Just print a warning when the theme doesn't provide 'theme_fg_color' and
    fallback to black color.
    
    Closes https://gitlab.gnome.org/GNOME/gnome-software/-/issues/1228

 src/gs-feature-tile.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)
---
diff --git a/src/gs-feature-tile.c b/src/gs-feature-tile.c
index 1c85083eb..158af1e56 100644
--- a/src/gs-feature-tile.c
+++ b/src/gs-feature-tile.c
@@ -268,7 +268,6 @@ gs_feature_tile_refresh (GsAppTile *self)
                if (key_colors != tile->key_colors_cache) {
                        g_autoptr(GArray) colors = NULL;
                        GdkRGBA fg_rgba;
-                       gboolean fg_rgba_valid;
                        GsHSBC fg_hsbc;
 
                        /* Look up the foreground colour for the feature tile,
@@ -283,8 +282,17 @@ gs_feature_tile_refresh (GsAppTile *self)
                         * @min_abs_contrast contrast with the foreground, so
                         * that the text is legible.
                         */
-                       fg_rgba_valid = gtk_style_context_lookup_color (context, "theme_fg_color", &fg_rgba);
-                       g_assert (fg_rgba_valid);
+                       if (!gtk_style_context_lookup_color (context, "theme_fg_color", &fg_rgba)) {
+                               static gboolean i_know = FALSE;
+                               if (!i_know) {
+                                       i_know = TRUE;
+                                       g_warning ("The theme doesn't provide 'theme_fg_color', fallbacking 
to black");
+                               }
+                               fg_rgba.red = 0.0;
+                               fg_rgba.green = 0.0;
+                               fg_rgba.blue = 0.0;
+                               fg_rgba.alpha = 1.0;
+                       }
 
                        gtk_rgb_to_hsv (fg_rgba.red, fg_rgba.green, fg_rgba.blue,
                                        &fg_hsbc.hue, &fg_hsbc.saturation, &fg_hsbc.brightness);