private void setSuffix(String s) {
    setSuff(s, s.length());
  }
*
YCS: this was the one place where lookup was not followed by return.
So restructure it. if ((j>0)&&(lookup(word.toString())) &&
!((word.charAt(j) == 's') && (word.charAt(j-1) == 's'))) return;
***
linguistics/src/main/java/com/yahoo/language/simple/kstem/KStemmer.java