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Overview
Comment:Fix incorrect column-usage accounting associated with generated columns and added by check-in [6601da58032d18ae]. Fix for ticket [b92e5e8ec2cdbaa1].
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SHA3-256: 9d75e1ccc72e9f536f45df3b24e9ecd25076cc1f7cf16b806b19e0e1b68e8326
User & Date: drh 2019-12-08 00:06:39
Context
2019-12-09
02:20
Fix possible null pointer dereferences in the fts5_expr() scalar function. (check-in: c5d44143 user: dan tags: trunk)
2019-12-08
00:06
Fix incorrect column-usage accounting associated with generated columns and added by check-in [6601da58032d18ae]. Fix for ticket [b92e5e8ec2cdbaa1]. (check-in: 9d75e1cc user: drh tags: trunk)
2019-12-07
13:42
Correctly deal with multi-row VALUES clauses that contain window functions. (check-in: 26d991f2 user: drh tags: trunk)
Changes
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Changes to src/resolve.c.

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    }
    pParse->checkSchema = 1;
    pTopNC->nErr++;
  }

  /* If a column from a table in pSrcList is referenced, then record
  ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes
  ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.

  **
  ** The colUsed mask is an optimization used to help determine if an
  ** index is a covering index.  The correct answer is still obtained
  ** if the mask contains extra bits.  But omitting bits from the mask
  ** might result in an incorrect answer.

  **
  ** The high-order bit of the mask is a "we-use-them-all" bit.
  ** If the column number is greater than the number of bits in the bitmask
  ** then set the high-order bit of the bitmask.  Also set the high-order
  ** bit if the column is a generated column, as that adds dependencies
  ** that are difficult to track, so we assume that all columns are used.
  */
  if( pExpr->iColumn>=0 && pMatch!=0 ){
    int n = pExpr->iColumn;

    testcase( n==BMS-1 );
    if( n>=BMS ){
      n = BMS-1;
    }
    assert( pExpr->y.pTab!=0 );

    assert( pMatch->iCursor==pExpr->iTable );
    if( pExpr->y.pTab->tabFlags & TF_HasGenerated ){
      Column *pColumn = pExpr->y.pTab->aCol + pExpr->iColumn;
      if( pColumn->colFlags & COLFLAG_GENERATED ) n = BMS-1;








    }
    pMatch->colUsed |= ((Bitmask)1)<<n;
  }

  /* Clean up and return
  */
  sqlite3ExprDelete(db, pExpr->pLeft);








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    }
    pParse->checkSchema = 1;
    pTopNC->nErr++;
  }

  /* If a column from a table in pSrcList is referenced, then record
  ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes
  ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  Bit 63 is
  ** set if the 63rd or any subsequent column is used.
  **
  ** The colUsed mask is an optimization used to help determine if an
  ** index is a covering index.  The correct answer is still obtained
  ** if the mask contains extra set bits.  However, it is important to
  ** avoid setting bits beyond the maximum column number of the table.
  ** (See ticket [b92e5e8ec2cdbaa1]).
  **

  ** If a generated column is referenced, set bits for every column
  ** of the table.


  */
  if( pExpr->iColumn>=0 && pMatch!=0 ){
    int n = pExpr->iColumn;
    Table *pTab;
    testcase( n==BMS-1 );
    if( n>=BMS ){
      n = BMS-1;
    }
    pTab = pExpr->y.pTab;
    assert( pTab!=0 );
    assert( pMatch->iCursor==pExpr->iTable );
    if( pTab->tabFlags & TF_HasGenerated ){
      Column *pColumn = pTab->aCol + pExpr->iColumn;
      if( pColumn->colFlags & COLFLAG_GENERATED ){
        testcase( pTab->nCol==63 );
        testcase( pTab->nCol==64 );
        if( pTab->nCol>=64 ){
          pMatch->colUsed = ALLBITS;
        }else{
          pMatch->colUsed = MASKBIT(pTab->nCol)-1;
        }
      }
    }
    pMatch->colUsed |= ((Bitmask)1)<<n;
  }

  /* Clean up and return
  */
  sqlite3ExprDelete(db, pExpr->pLeft);
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