Index: src/insert.c
==================================================================
--- src/insert.c
+++ src/insert.c
@@ -1446,11 +1446,11 @@
       /* An ON CONFLICT DO NOTHING clause, without a constraint-target.
       ** Make all unique constraint resolution be OE_Ignore */
       assert( pUpsert->pUpsertSet==0 );
       overrideError = OE_Ignore;
       pUpsert = 0;
-    }else if( (pUpIdx = pUpsert->pUpsertIdx)!=0 ){
+    }else if( (pUpIdx = pUpsert->pUpsertIdx)!=0 && pUpIdx->pNext!=0 ){
       /* If the constraint-target is on some column other than
       ** then ROWID, then we might need to move the UPSERT around
       ** so that it occurs in the correct order. */
       sAddr.upsertTop = sAddr.upsertTop2 = sqlite3VdbeMakeLabel(v);
       sAddr.upsertBtm = sqlite3VdbeMakeLabel(v);
@@ -1606,11 +1606,11 @@
     int regR;            /* Range of registers holding conflicting PK */
     int iThisCur;        /* Cursor for this UNIQUE index */
     int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */
 
     if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
-    if( pUpIdx==pIdx ){
+    if( pUpIdx==pIdx && pIdx->pNext!=0 ){
       addrUniqueOk = sAddr.upsertBtm;
       upsertBypass = sqlite3VdbeGoto(v, 0);
       VdbeComment((v, "Skip upsert subroutine"));
       sqlite3VdbeResolveLabel(v, sAddr.upsertTop2);
     }else{
@@ -1816,11 +1816,11 @@
             (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
         seenReplace = 1;
         break;
       }
     }
-    if( pUpIdx==pIdx ){
+    if( pUpIdx==pIdx && pIdx->pNext!=0 ){
       sqlite3VdbeJumpHere(v, upsertBypass);
     }else{
       sqlite3VdbeResolveLabel(v, addrUniqueOk);
     }
     sqlite3ExprCachePop(pParse);