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Overview
Comment:Do not allow a column reference that is converted into a constant by the WHERE-clause constant propagation optimization to be moved to the init-time constant expression list, as the table reference will not work there. This fixes a problem found by OSSFuzz.
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SHA3-256: d30b2a947313b146f29e2b53f0fd471409fda7938151241d3fb5863614f88999
User & Date: drh 2018-07-28 16:24:08.475
Context
2018-07-28
21:01
Add a small cost penalty to sorting to bias the query planner in favor of plans that do not require a final sorting pass. (check-in: 85b9beb460 user: drh tags: trunk)
16:24
Do not allow a column reference that is converted into a constant by the WHERE-clause constant propagation optimization to be moved to the init-time constant expression list, as the table reference will not work there. This fixes a problem found by OSSFuzz. (check-in: d30b2a9473 user: drh tags: trunk)
14:56
Fix an assert() statement that was made obsolete by the constant propagation enhancement. Problem discovered by OSSFuzz. (check-in: e4b4737e34 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/expr.c.
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    case TK_COLUMN:
    case TK_AGG_FUNCTION:
    case TK_AGG_COLUMN:
      testcase( pExpr->op==TK_ID );
      testcase( pExpr->op==TK_COLUMN );
      testcase( pExpr->op==TK_AGG_FUNCTION );
      testcase( pExpr->op==TK_AGG_COLUMN );
      if( ExprHasProperty(pExpr, EP_FixedCol) ){
        return WRC_Continue;
      }
      if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
        return WRC_Continue;
      }
      /* Fall through */
    case TK_IF_NULL_ROW:








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    case TK_COLUMN:
    case TK_AGG_FUNCTION:
    case TK_AGG_COLUMN:
      testcase( pExpr->op==TK_ID );
      testcase( pExpr->op==TK_COLUMN );
      testcase( pExpr->op==TK_AGG_FUNCTION );
      testcase( pExpr->op==TK_AGG_COLUMN );
      if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){
        return WRC_Continue;
      }
      if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
        return WRC_Continue;
      }
      /* Fall through */
    case TK_IF_NULL_ROW:
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** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
  return exprIsConst(p, 1, 0);
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant
** that does no originate from the ON or USING clauses of a join.
** Return 0 if it involves variables or function calls or terms from
** an ON or USING clause.







*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
  return exprIsConst(p, 2, 0);
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant








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** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
  return exprIsConst(p, 1, 0);
}

/*
** Walk an expression tree.  Return non-zero if
**
**   (1) the expression is constant, and
**   (2) the expression does originate in the ON or USING clause
**       of a LEFT JOIN, and
**   (3) the expression does not contain any EP_FixedCol TK_COLUMN
**       operands created by the constant propagation optimization.
**
** When this routine returns true, it indicates that the expression
** can be added to the pParse->pConstExpr list and evaluated once when
** the prepared statement starts up.  See sqlite3ExprCodeAtInit().
*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
  return exprIsConst(p, 2, 0);
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant
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Changes to test/fuzzdata5.db.

cannot compute difference between binary files