techee commented on this pull request.
ctype = g_content_type_guess(path, NULL, 0, NULL); icon = g_content_type_get_icon(ctype); g_free(ctype);
if (icon != NULL) { - gtk_icon_size_lookup(GTK_ICON_SIZE_MENU, &width, NULL); - info = gtk_icon_theme_lookup_by_gicon(gtk_icon_theme_get_default(), icon, width, GTK_ICON_LOOKUP_USE_BUILTIN); - g_object_unref(icon); + info = gtk_icon_theme_lookup_by_gicon(gtk_icon_theme_get_default(), icon, 16, 0);
Notice that the constant GTK_ICON_LOOKUP_USE_BUILTIN was used for the last parameter which is flags - I believe this is why the icons looked differently on macOS so I used 0.
The width was determined by https://developer.gnome.org/gtk3/stable/gtk3-Themeable-Stock-Images.html#gtk... but based on the documentation this function shouldn't be needed and GTK_ICON_SIZE_MENU is 16px. I use the same in ProjectOrganizer and it seems to work fine.