Attempted fix for GUI2 event firing test failures

Commit 315f849 broke the test in two ways. First, I intentionally
changed pre and post events to be passed to the target widget as well, not
only its ancestors. The test verified that the events were *not* passed to
the target widget. Fixed by adjusting the test to verify that the target
widget now does receive the event.

Second, I unintentionally stopped the event dispatcher from receiving pre
and post events. Fixed.

src/gui/core/event/dispatcher_private.hpp

@@ -305,11 +305,15 @@ build_event_chain(const ui_event event, widget* dispatcher, widget* w)
 
 	std::vector<std::pair<widget*, ui_event>> result;
 
-	while(w != dispatcher) {
+	while(true) {
 		if(w->has_event(event, dispatcher::event_queue_type(dispatcher::pre | dispatcher::post))) {
 			result.emplace_back(w, event);
 		}
 
+		if(w == dispatcher) {
+			break;
+		}
+
 		w = w->parent();
 		assert(w);
 	}

src/tests/gui/fire_event.cpp

@@ -94,12 +94,13 @@ static void add_widget(gui2::grid& grid
 static std::string set_event_order()
 {
 	return
-			"pre:root\n"
-			"pre:level 1\n"
-			"child:level 2\n"
-			"post:level 1\n"
-			"post:root\n";
-
+		"pre:root\n"
+		"pre:level 1\n"
+		"pre:level 2\n"
+		"child:level 2\n"
+		"post:level 2\n"
+		"post:level 1\n"
+		"post:root\n";
 }
 
 /** @todo Add the rest of the events. */