The more important check here is that msgbuf contains something, not that it exists.

event.cc

@@ -59,7 +59,7 @@ _EVENT(PRIVMSG) {
 	int argc = 0;
 	int nargmax = 1;
 	char **argv = (char**)calloc(nargmax, sizeof(char*));
-	if(msgbuf) {
+	if(msgbuf && *msgbuf != '\0') {
 		int argstart = 0;
 		for(unsigned int i = 0; i <= strlen(msgbuf); ++i) {
 			if(msgbuf[i] == ' ' || msgbuf[i] == '\0') {