Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -3693,12 +3693,12 @@
       pLoop = pLast;
     }
     if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
       if( pLoop->u.vtab.isOrdered ) obSat = obDone;
       break;
-    }else{
-      pLoop->u.btree.nIdxCol = 0;
+    }else if( wctrlFlags & WHERE_DISTINCTBY ){
+      pLoop->u.btree.nDistinctCol = 0;
     }
     iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
 
     /* Mark off any ORDER BY term X that is a column in the table of
     ** the current loop for which there is term in the WHERE
@@ -3836,11 +3836,13 @@
           }
           if( iColumn!=XN_ROWID ){
             pColl = sqlite3ExprNNCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
             if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
           }
-          pLoop->u.btree.nIdxCol = j+1;
+          if( wctrlFlags & WHERE_DISTINCTBY ){
+            pLoop->u.btree.nDistinctCol = j+1;
+          }
           isMatch = 1;
           break;
         }
         if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
           /* Make sure the sort order is compatible in an ORDER BY clause.
@@ -5157,11 +5159,11 @@
       int n;
       if( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED
        && i==pWInfo->nLevel-1  /* Ticket [ef9318757b152e3] 2017-10-21 */
        && (pLoop->wsFlags & WHERE_INDEXED)!=0
        && (pIdx = pLoop->u.btree.pIndex)->hasStat1
-       && (n = pLoop->u.btree.nIdxCol)>0
+       && (n = pLoop->u.btree.nDistinctCol)>0
        && pIdx->aiRowLogEst[n]>=36
       ){
         int r1 = pParse->nMem+1;
         int j, op;
         for(j=0; j<n; j++){

Index: src/whereInt.h
==================================================================
--- src/whereInt.h
+++ src/whereInt.h
@@ -126,11 +126,11 @@
   union {
     struct {               /* Information for internal btree tables */
       u16 nEq;               /* Number of equality constraints */
       u16 nBtm;              /* Size of BTM vector */
       u16 nTop;              /* Size of TOP vector */
-      u16 nIdxCol;           /* Index column used for ORDER BY */
+      u16 nDistinctCol;      /* Index columns used to sort for DISTINCT */
       Index *pIndex;         /* Index used, or NULL */
     } btree;
     struct {               /* Information for virtual tables */
       int idxNum;            /* Index number */
       u8 needFree;           /* True if sqlite3_free(idxStr) is needed */

Index: test/distinct2.test
==================================================================
--- test/distinct2.test
+++ test/distinct2.test
@@ -226,8 +226,54 @@
   INSERT INTO t2 VALUES('yes');
   SELECT DISTINCT a FROM t1, t2 WHERE x=b;
   ANALYZE;
   SELECT DISTINCT a FROM t1, t2 WHERE x=b;
 } {1 1}
+
+#-------------------------------------------------------------------------
+reset_db
+
+do_execsql_test 2000 {
+  CREATE TABLE t0 (c0, c1, c2, PRIMARY KEY (c0, c1));
+  CREATE TABLE t1 (c2);
+  INSERT INTO t0(c2) VALUES (0),(1),(3),(4),(5),(6),(7),(8),(9),(10),(11);
+  INSERT INTO t0(c1) VALUES ('a');
+  INSERT INTO t1(c2) VALUES (0);
+}
+do_execsql_test 2010 {
+  SELECT DISTINCT t0.c0, t1._rowid_, t0.c1 FROM t1 CROSS JOIN t0 ORDER BY t0.c0;
+} {{} 1 {} {} 1 a}
+do_execsql_test 1.2 {
+  ANALYZE;
+}
+do_execsql_test 2020 {
+  SELECT DISTINCT t0.c0, t1._rowid_, t0.c1 FROM t1 CROSS JOIN t0 ORDER BY t0.c0;
+} {{} 1 {} {} 1 a}
+
+
+do_execsql_test 2030 {
+  CREATE TABLE t2(a, b, c);
+  CREATE INDEX t2ab ON t2(a, b);
+  
+  WITH c(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM c WHERE i<64)
+    INSERT INTO t2 SELECT 'one', i%2, 'one' FROM c;
+
+  WITH c(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM c WHERE i<64)
+    INSERT INTO t2 SELECT 'two', i%2, 'two' FROM c;
+
+  CREATE TABLE t3(x INTEGER PRIMARY KEY);
+  INSERT INTO t3 VALUES(1);
+
+  ANALYZE;
+}
+do_execsql_test 2040 {
+  SELECT DISTINCT a, b, x FROM t3 CROSS JOIN t2 ORDER BY a; 
+} {
+  one 0 1
+  one 1 1
+  two 0 1
+  two 1 1
+}
+
 
 
 finish_test