When an INSERT is receiving content from a SELECT, run an OP_ReleaseReg opcode

at the top of each iteration of the loop in order to prevent spurious
OP_SCopy misuse complaints.  Ticket [de4b04149b9fdeae]

FossilOrigin-Name: 6afadd3b3a40b0ef29fd14fb24c2a4b9479483e5f8b9125ce02d8daae662207f

src/insert.c

@@ -1020,6 +1020,7 @@ void sqlite3Insert(
     **         goto C
     **      D: ...
     */
+    sqlite3VdbeReleaseRegisters(pParse, regData, pTab->nCol, 0);
     addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
     VdbeCoverage(v);
     if( ipkColumn>=0 ){
@@ -1280,6 +1281,15 @@ void sqlite3Insert(
     sqlite3VdbeAddOp1(v, OP_Close, srcTab);
   }else if( pSelect ){
     sqlite3VdbeGoto(v, addrCont);
+#ifdef SQLITE_DEBUG
+    /* If we are jumping back to an OP_Yield that is preceded by an
+    ** OP_ReleaseReg, set the p5 flag on the OP_Goto so that the
+    ** OP_ReleaseReg will be included in the loop. */
+    if( sqlite3VdbeGetOp(v, addrCont-1)->opcode==OP_ReleaseReg ){
+      assert( sqlite3VdbeGetOp(v, addrCont)->opcode==OP_Yield );
+      sqlite3VdbeChangeP5(v, 1);
+    }
+#endif
     sqlite3VdbeJumpHere(v, addrInsTop);
   }
 

src/vdbe.c

@@ -845,6 +845,20 @@ int sqlite3VdbeExec(
 ** to the current line should be indented for EXPLAIN output.
 */
 case OP_Goto: {             /* jump */
+
+#ifdef SQLITE_DEBUG
+  /* In debuggging mode, when the p5 flags is set on an OP_Goto, that
+  ** means we should really jump back to the preceeding OP_ReleaseReg
+  ** instruction. */
+  if( pOp->p5 ){
+    assert( pOp->p2 < (int)(pOp - aOp) );
+    assert( pOp->p2 > 1 );
+    pOp = &aOp[pOp->p2 - 2];
+    assert( pOp[1].opcode==OP_ReleaseReg );
+    goto check_for_interrupt;
+  }
+#endif
+
 jump_to_p2_and_check_for_interrupt:
   pOp = &aOp[pOp->p2 - 1];
 

src/where.c

@@ -870,8 +870,8 @@ static void constructAutomaticIndex(
     pTabItem->fg.viaCoroutine = 0;
   }else{
     sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
+    sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
   }
-  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
   sqlite3VdbeJumpHere(v, addrTop);
   sqlite3ReleaseTempReg(pParse, regRecord);