** changes "x IN (?)" into "x=?". */
      }
    }else if( eOp & (WO_EQ|WO_IS) ){
      int iCol = pProbe->aiColumn[saved_nEq];
      pNew->wsFlags |= WHERE_COLUMN_EQ;
      assert( saved_nEq==pNew->u.btree.nEq );
      if( iCol==XN_ROWID 
       || (iCol>=0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
      ){
        if( iCol>=0 && pProbe->uniqNotNull==0 ){
          pNew->wsFlags |= WHERE_UNQ_WANTED;
        }else{
          pNew->wsFlags |= WHERE_ONEROW;
        }
      }

do_catchsql_test 2.1 {
  SELECT * FROM aa LEFT JOIN cc ON (a=b) JOIN bb ON (b=c);
} {1 {ON clause references tables to its right}}
do_catchsql_test 2.2 {
  SELECT * FROM aa JOIN cc ON (a=b) JOIN bb ON (b=c);
} {0 {one one one}}

#-------------------------------------------------------------------------
# Test that a problem causing where.c to overlook opportunities to
# omit unnecessary tables from a LEFT JOIN when UNIQUE, NOT NULL column 
# that makes this possible happens to be the leftmost in its table.
#
reset_db
do_execsql_test 3.0 {
  CREATE TABLE t1(k1 INTEGER PRIMARY KEY, k2, k3);
  CREATE TABLE t2(k2 INTEGER PRIMARY KEY, v2);

  -- Prior to this problem being fixed, table t3_2 would be omitted from
  -- the join queries below, but if t3_1 were used in its place it would
  -- not.
  CREATE TABLE t3_1(k3 PRIMARY KEY, v3) WITHOUT ROWID;
  CREATE TABLE t3_2(v3, k3 PRIMARY KEY) WITHOUT ROWID;
}

do_eqp_test 3.1 {
  SELECT v2 FROM t1 LEFT JOIN t2 USING (k2) LEFT JOIN t3_1 USING (k3);
} {
  0 0 0 {SCAN TABLE t1} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
}

do_eqp_test 3.2 {
  SELECT v2 FROM t1 LEFT JOIN t2 USING (k2) LEFT JOIN t3_2 USING (k3);
} {
  0 0 0 {SCAN TABLE t1} 
  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
}

finish_test