fix

teensy4/Stream.cpp

 bool  Stream::findUntil(const char *target, const char *terminator)
 {
   if(target == NULL) return true;
-  if(terminator == NULL) return true;	
-  return findUntil(target, strlen(target), terminator, strlen(terminator));
+  size_t tlen = (terminator==NULL)?0:strlen(terminator);
+  return findUntil(target, strlen(target), terminator, tlen);
 }
 
 // reads data from the stream until the target string of the given length is found
 
   if( target == NULL) return true;
   if( *target == 0) return true;   // return true if target is a null string
-  if(terminator == NULL) return true;
+  if (terminator == NULL) termLen = 0;
 	
   while( (c = timedRead()) > 0){
     if( c == target[index]){