add preference to not get addon icons

also skip if DataURI is too large

data/advanced_preferences.cfg

@@ -21,6 +21,14 @@
     [/option]
 [/advanced_preference]
 
+[advanced_preference]
+    field=addon_icons
+    name= _ "Whether to show icons in the add-ons list on the add-ons manager"
+    description= _ "Disabling saves bandwidth by not sending icons for the add-ons list in the add-ons manager"
+    type=boolean
+    default=yes
+[/advanced_preference]
+
 [advanced_preference]
     field=ask_delete
     name= _ "Confirm deleting saves"

src/addon/client.cpp

@@ -112,16 +112,20 @@ void addons_client::connect()
 			   << " supports: " << utils::join(server_capabilities_, " ");
 }
 
-bool addons_client::request_addons_list(config& cfg)
+bool addons_client::request_addons_list(config& cfg, bool icons)
 {
 	cfg.clear();
 
+	config request;
+	config& req_child = request.add_child("request_campaign_list");
+	req_child["send_icons"] = icons;
+
 	config response_buf;
 
 	/** @todo FIXME: get rid of this legacy "campaign"/"campaigns" silliness
 	 */
 
-	send_simple_request("request_campaign_list", response_buf);
+	send_request(request, response_buf);
 	wait_for_transfer_done(_("Downloading list of add-ons..."));
 
 	std::swap(cfg, response_buf.mandatory_child("campaigns"));

src/addon/client.hpp

@@ -89,8 +89,9 @@ public:
 	 *
 	 * @param cfg A config object whose contents are replaced with
 	 *            the server's list if available, cleared otherwise.
+	 * @param icons Whether to have the add-ons server populate the icon
 	 */
-	bool request_addons_list(config& cfg);
+	bool request_addons_list(config& cfg, bool icons);
 
 	/**
 	 * Retrieves the add-ons server web URL if available.

src/addon/info.cpp

@@ -233,9 +233,7 @@ std::string addon_info::display_icon() const
 {
 	std::string ret = icon;
 
-	if(ret.empty()) {
-		ERR_AC << "add-on '" << id << "' doesn't have an icon path set";
-	} else if(!image::exists(image::locator{ret})) {
+	if(!image::exists(image::locator{ret}) && !ret.empty()) {
 		ERR_AC << "add-on '" << id << "' has an icon which cannot be found: '" << ret << "'";
 	} else if(ret.find("units/") != std::string::npos && ret.find_first_of('~') == std::string::npos) {
 		// HACK: prevent magenta icons, because they look awful

src/addon/manager_ui.cpp

@@ -55,7 +55,7 @@ bool get_addons_list(addons_client& client, addons_list& list)
 	list.clear();
 
 	config cfg;
-	client.request_addons_list(cfg);
+	client.request_addons_list(cfg, prefs::get().addon_icons());
 
 	read_addons_list(cfg, list);
 

src/gui/dialogs/addon/manager.cpp

@@ -539,7 +539,7 @@ void addon_manager::toggle_details(button& btn, stacked_widget& stk)
 
 void addon_manager::fetch_addons_list()
 {
-	bool success = client_.request_addons_list(cfg_);
+	bool success = client_.request_addons_list(cfg_, prefs::get().addon_icons());
 	if(!success) {
 		gui2::show_error_message(_("An error occurred while downloading the add-ons list from the server."));
 		close();

src/preferences/preferences.hpp

@@ -485,6 +485,7 @@ public:
 	 */
 	void set_sub_achievement(const std::string& content_for, const std::string& id, const std::string& sub_id);
 
+	PREF_GETTER_SETTER(addon_icons, bool, true)
 	PREF_GETTER_SETTER(show_ally_orb, bool, game_config::show_ally_orb)
 	PREF_GETTER_SETTER(show_status_on_ally_orb, bool, game_config::show_status_on_ally_orb)
 	PREF_GETTER_SETTER(show_enemy_orb, bool, game_config::show_enemy_orb)
@@ -811,6 +812,7 @@ private:
 		prefs_list::sp_modifications,
 		prefs_list::animate_map,
 		prefs_list::animate_water,
+		prefs_list::addon_icons,
 	};
 	static constexpr std::array synced_children_{
 		prefs_list::acquaintance,

src/preferences/preferences_list.hpp

@@ -32,6 +32,8 @@ struct preferences_list_defines
 	ADDPREF(achievements)
 	/** player names marked as either friends or as ignored */
 	ADDPREF(acquaintance)
+	/** whether to get the add-on icons when downloading the add-ons list */
+	ADDPREF(addon_icons)
 	/** the sort direction, ie: ascending */
 	ADDPREF(addon_manager_saved_order_direction)
 	/** the name of the column in the add-ons manager to use by default to sort results */
@@ -554,7 +556,8 @@ struct preferences_list_defines
 		turn_changed_lobby,
 		game_created_sound,
 		game_created_notif,
-		game_created_lobby
+		game_created_lobby,
+		addon_icons
 	)
 };
 using prefs_list = string_enums::enum_base<preferences_list_defines>;

src/server/campaignd/server.cpp

@@ -1047,6 +1047,11 @@ void server::handle_request_campaign_list(const server::request& req)
 		// or irrelevant to clients
 		j.remove_attributes("passphrase", "passhash", "passsalt", "upload_ip", "email");
 
+		// don't include icons if requested
+		if(!req.cfg["send_icons"].to_bool(true)) {
+			j.remove_attribute("icon");
+		}
+
 		// Build a feedback_url string attribute from the internal [feedback]
 		// data or deliver an empty value, in case clients decide to assume its
 		// presence.