Support for escaping _ (underscores) in triggers

Author: Marcel Overdijk

rivescript-core/src/main/java/com/rivescript/RiveScript.java

@@ -1478,7 +1478,8 @@ private String triggerRegexp(String user, Client profile, String trigger) {
 		// Simple regexps are simple.
 		regexp = regexp.replaceAll("\\*", "(.+?)");                  // *  ->  (.+?)
 		regexp = regexp.replaceAll("#", "(\\\\d+?)");                // #  ->  (\d+?)
-		regexp = regexp.replaceAll("_", "(\\\\w+?)");                // _  ->  ([A-Za-z ]+?)
+		regexp = regexp.replaceAll("(?<!\\\\)_", "(\\\\w+?)");       // _  ->  ([A-Za-z ]+?)
+		regexp = regexp.replaceAll("\\\\_", "_");                    // \_ ->  _
 		regexp = regexp.replaceAll("\\s*\\{weight=\\d+\\}\\s*", ""); // Remove {weight} tags
 		regexp = regexp.replaceAll("<zerowidthstar>", "(.*?)");      // *  ->  (.*?)
 
@@ -1989,7 +1990,7 @@ private String formatMessage(String message) {
 		message = Util.substitute(subs_s, subs, message);
 
 		// Sanitize what's left.
-		message = message.replaceAll("[^a-z0-9 ]", "");
+		message = message.replaceAll("[^a-z0-9_ ]", "");
 		return message;
 	}