workbench: Fix crash when a monitored entry is removed

When a monitored file or directory is removed, we call the handler for
that event directly.  However, this might lead to removing our own
monitoring entry, which means we must not reference it any further
after having called the handler.

Fixes #1430.

Author: b4n

workbench/src/wb_monitor.c

@@ -90,13 +90,14 @@ static void wb_monitor_entry_free (gpointer data)
 
 /* Callback function for file monitoring. */
 static void wb_monitor_file_changed_cb(G_GNUC_UNUSED GFileMonitor *monitor,
-									   G_GNUC_UNUSED GFile *file,
-									   G_GNUC_UNUSED GFile *other_file,
+									   GFile *file,
+									   GFile *other_file,
 									   GFileMonitorEvent event,
 									   WB_MONITOR_ENTRY *entry)
 {
 	const gchar *event_string = NULL;
 	gchar *file_path, *other_file_path = NULL;
+	void (*handler) (WORKBENCH *, WB_PROJECT *, WB_PROJECT_DIR *, const gchar *) = NULL;
 
 	g_return_if_fail(entry != NULL);
 
@@ -111,14 +112,12 @@ static void wb_monitor_file_changed_cb(G_GNUC_UNUSED GFileMonitor *monitor,
 	{
 		case G_FILE_MONITOR_EVENT_CREATED:
 			event_string = "FILE_CREATED";
-			workbench_process_add_file_event (wb_globals.opened_wb,
-				entry->prj, entry->dir, file_path);
+			handler = workbench_process_add_file_event;
 			break;
 
 		case G_FILE_MONITOR_EVENT_DELETED:
 			event_string = "FILE_DELETED";
-			workbench_process_remove_file_event (wb_globals.opened_wb,
-				entry->prj, entry->dir, file_path);
+			handler = workbench_process_remove_file_event;
 			break;
 
 		default:
@@ -131,6 +130,13 @@ static void wb_monitor_file_changed_cb(G_GNUC_UNUSED GFileMonitor *monitor,
 			wb_project_dir_get_name(entry->dir), event_string, file_path);
 	}
 
+	if (handler != NULL)
+	{
+		/* The handler might destroy the entry, so we mustn't reference it any
+		 * further after calling it */
+		handler (wb_globals.opened_wb, entry->prj, entry->dir, file_path);
+	}
+
 	g_free(file_path);
 	g_free(other_file_path);
 }