Index: src/update.c
==================================================================
--- src/update.c
+++ src/update.c
@@ -600,25 +600,25 @@
       sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
     }else{
       j = aXRef[i];
       if( j>=0 ){
         sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
-        if( tmask&TRIGGER_BEFORE ){
-          /* Must preserve copied values even in case the original is
-          ** reloaded in the After-BEFORE-trigger-reload-loop below.
-          ** Ticket d85fffd6ffe856092ed8daefa811b1e399706b28 */
-          sqlite3VdbeSwapOpcode(v, -1, OP_SCopy, OP_Copy);
-        }
       }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
         /* This branch loads the value of a column that will not be changed 
         ** into a register. This is done if there are no BEFORE triggers, or
         ** if there are one or more BEFORE triggers that use this value via
         ** a new.* reference in a trigger program.
         */
         testcase( i==31 );
         testcase( i==32 );
         sqlite3ExprCodeGetColumnToReg(pParse, pTab, i, iDataCur, regNew+i);
+        if( tmask & TRIGGER_BEFORE ){
+          /* This value will be recomputed in After-BEFORE-trigger-reload-loop
+          ** below, so make sure that it is not cached and reused.
+          ** Ticket d85fffd6ffe856092ed8daefa811b1e399706b28. */
+          sqlite3ExprCacheRemove(pParse, regNew+i, 1);
+        }
       }else{
         sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
       }
     }
   }

Index: src/vdbe.h
==================================================================
--- src/vdbe.h
+++ src/vdbe.h
@@ -198,11 +198,10 @@
 # define sqlite3VdbeVerifyNoResultRow(A)
 #endif
 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
 void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
-void sqlite3VdbeSwapOpcode(Vdbe*, u32 addr, u8, u8);
 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
 void sqlite3VdbeJumpHere(Vdbe*, int addr);

Index: src/vdbeaux.c
==================================================================
--- src/vdbeaux.c
+++ src/vdbeaux.c
@@ -841,16 +841,10 @@
 void sqlite3VdbeChangeP5(Vdbe *p, u16 p5){
   assert( p->nOp>0 || p->db->mallocFailed );
   if( p->nOp>0 ) p->aOp[p->nOp-1].p5 = p5;
 }
 
-/* Change the opcode to iNew if it was previously iOld */
-void sqlite3VdbeSwapOpcode(Vdbe *p, u32 addr, u8 iOld, u8 iNew){
-  VdbeOp *pOp = sqlite3VdbeGetOp(p,addr);
-  if( pOp->opcode==iOld ) pOp->opcode = iNew;
-}
-
 /*
 ** Change the P2 operand of instruction addr so that it points to
 ** the address of the next instruction to be coded.
 */
 void sqlite3VdbeJumpHere(Vdbe *p, int addr){

Index: test/trigger1.test
==================================================================
--- test/trigger1.test
+++ test/trigger1.test
@@ -758,8 +758,14 @@
   CREATE TABLE t19(a INT PRIMARY KEY, b, c)WITHOUT ROWID;
   INSERT INTO t19(a,b,c) VALUES(1,2,3);
   CREATE TRIGGER t19r3 BEFORE UPDATE ON t19 BEGIN SELECT new.b; END;
   UPDATE t19 SET c=b WHERE a=1;
   SELECT * FROM t19;
+} {1 2 2}
+do_execsql_test trigger1-19.1 {
+  DELETE FROM t19;
+  INSERT INTO t19(a,b,c) VALUES(1,2,3);
+  UPDATE t19 SET c=CASE WHEN b=2 THEN b ELSE b+99 END WHERE a=1;
+  SELECT * FROM t19;
 } {1 2 2}
 
 finish_test