Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -1086,11 +1086,11 @@
 static int dupedExprStructSize(Expr *p, int flags){
   int nSize;
   assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
   assert( EXPR_FULLSIZE<=0xfff );
   assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
-  if( 0==flags ){
+  if( 0==flags || p->op==TK_SELECT_COLUMN ){
     nSize = EXPR_FULLSIZE;
   }else{
     assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
     assert( !ExprHasProperty(p, EP_FromJoin) ); 
     assert( !ExprHasProperty(p, EP_MemToken) );
@@ -1229,10 +1229,12 @@
       }
     }else{
       if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
         if( pNew->op==TK_SELECT_COLUMN ){
           pNew->pLeft = p->pLeft;
+          assert( p->iColumn==0 || p->pRight==0 );
+          assert( p->pRight==0  || p->pRight==p->pLeft );
         }else{
           pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
         }
         pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
       }
@@ -1291,10 +1293,11 @@
 }
 ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
   ExprList *pNew;
   struct ExprList_item *pItem, *pOldItem;
   int i;
+  Expr *pPriorSelectCol = 0;
   assert( db!=0 );
   if( p==0 ) return 0;
   pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
   if( pNew==0 ) return 0;
   pNew->nExpr = i = p->nExpr;
@@ -1305,11 +1308,28 @@
     return 0;
   } 
   pOldItem = p->a;
   for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
     Expr *pOldExpr = pOldItem->pExpr;
+    Expr *pNewExpr;
     pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
+    if( pOldExpr 
+     && pOldExpr->op==TK_SELECT_COLUMN
+     && (pNewExpr = pItem->pExpr)!=0 
+    ){
+      assert( pNewExpr->iColumn==0 || i>0 );
+      if( pNewExpr->iColumn==0 ){
+        assert( pOldExpr->pLeft==pOldExpr->pRight );
+        pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight;
+      }else{
+        assert( i>0 );
+        assert( pItem[-1].pExpr!=0 );
+        assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );
+        assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );
+        pNewExpr->pLeft = pPriorSelectCol;
+      }
+    }
     pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
     pItem->sortOrder = pOldItem->sortOrder;
     pItem->done = 0;
     pItem->bSpanIsTab = pOldItem->bSpanIsTab;

Index: test/rowvalue.test
==================================================================
--- test/rowvalue.test
+++ test/rowvalue.test
@@ -331,7 +331,28 @@
   DELETE FROM x1 WHERE  a<(SELECT * FROM (SELECT b,2));
 } {1 {sub-select returns 2 columns - expected 1}}
 do_catchsql_test 15.5 {
   INSERT INTO x1(a,b) VALUES(1,(SELECT * FROM (SELECT 1,2))<3);
 } {1 {row value misused}}
+
+#-------------------------------------------------------------------------
+# Row-values used in UPDATE statements within TRIGGERs
+#
+# Ticket https://www.sqlite.org/src/info/8c9458e703666e1a
+#
+do_execsql_test 16.1 {
+  CREATE TABLE t16a(a,b,c);
+  INSERT INTO t16a VALUES(1,2,3);
+  CREATE TABLE t16b(x);
+  INSERT INTO t16b(x) VALUES(1);
+  CREATE TRIGGER t16r AFTER UPDATE ON t16b BEGIN
+     UPDATE t16a SET (a,b,c)=(SELECT new.x,new.x+1,new.x+2);
+  END;
+  UPDATE t16b SET x=7;
+  SELECT * FROM t16a;
+} {7 8 9}
+do_execsql_test 16.2 {
+  UPDATE t16b SET x=97;
+  SELECT * FROM t16a;
+} {97 98 99}
 
 finish_test