*** a/src/backend/utils/adt/tsquery_util.c
--- b/src/backend/utils/adt/tsquery_util.c
***************
*** 336,342 **** QTN2QT(QTNode *in)
  	cntsize(in, &sumlen, &nnode);
  	len = COMPUTESIZE(nnode, sumlen);
  
! 	out = (TSQuery) palloc(len);
  	SET_VARSIZE(out, len);
  	out->size = nnode;
  
--- 336,342 ----
  	cntsize(in, &sumlen, &nnode);
  	len = COMPUTESIZE(nnode, sumlen);
  
! 	out = (TSQuery) palloc0(len);
  	SET_VARSIZE(out, len);
  	out->size = nnode;