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Overview
Comment:Fix a problem in which nested CTEs with the same table name trick the code generator into thinking they are the same CTE, which then tries to use the manifest them both into the same transient table.
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SHA3-256:202dd033019dd27428e3cc5f6e164c95b37efe39e2753515112b201ddefca67b
User & Date: drh 2018-12-27 02:16:01
Context
2018-12-27
07:46
Fix a null-pointer dereference that could occur in fts5 with a corrupt database. check-in: b0a49d5e user: dan tags: trunk
02:16
Fix a problem in which nested CTEs with the same table name trick the code generator into thinking they are the same CTE, which then tries to use the manifest them both into the same transient table. check-in: 202dd033 user: drh tags: trunk
00:30
In the treeview debugging output, provide additional details for the Table object associated with each FROM clause term. check-in: 11d4682d user: drh tags: trunk
Changes
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Changes to src/select.c.

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*/
static struct SrcList_item *isSelfJoinView(
  SrcList *pTabList,           /* Search for self-joins in this FROM clause */
  struct SrcList_item *pThis   /* Search for prior reference to this subquery */
){
  struct SrcList_item *pItem;
  for(pItem = pTabList->a; pItem<pThis; pItem++){

    if( pItem->pSelect==0 ) continue;
    if( pItem->fg.viaCoroutine ) continue;
    if( pItem->zName==0 ) continue;
    if( sqlite3_stricmp(pItem->zDatabase, pThis->zDatabase)!=0 ) continue;
    if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;
    if( sqlite3ExprCompare(0, 
          pThis->pSelect->pWhere, pItem->pSelect->pWhere, -1) 
    ){




      /* The view was modified by some other optimization such as
      ** pushDownWhereTerms() */
      continue;
    }
    return pItem;
  }
  return 0;







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*/
static struct SrcList_item *isSelfJoinView(
  SrcList *pTabList,           /* Search for self-joins in this FROM clause */
  struct SrcList_item *pThis   /* Search for prior reference to this subquery */
){
  struct SrcList_item *pItem;
  for(pItem = pTabList->a; pItem<pThis; pItem++){
    Select *pS1;
    if( pItem->pSelect==0 ) continue;
    if( pItem->fg.viaCoroutine ) continue;
    if( pItem->zName==0 ) continue;
    if( sqlite3_stricmp(pItem->zDatabase, pThis->zDatabase)!=0 ) continue;
    if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;
    pS1 = pItem->pSelect;
    if( pThis->pSelect->selId!=pS1->selId ){
      /* The query flattener left two different CTE tables with identical
      ** names in the same FROM clause. */
      continue;
    }
    if( sqlite3ExprCompare(0, pThis->pSelect->pWhere, pS1->pWhere, -1) ){
      /* The view was modified by some other optimization such as
      ** pushDownWhereTerms() */
      continue;
    }
    return pItem;
  }
  return 0;

Changes to test/with1.test.

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#
do_execsql_test 20.1 {
  WITH c(i)AS(VALUES(9)UNION SELECT~i FROM c)SELECT max(5)>i fROM c;
} {0}
do_execsql_test 20.2 {
  WITH c(i)AS(VALUES(5)UNIoN SELECT 0)SELECT min(1)-i fROM c;
} {1}




















finish_test








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#
do_execsql_test 20.1 {
  WITH c(i)AS(VALUES(9)UNION SELECT~i FROM c)SELECT max(5)>i fROM c;
} {0}
do_execsql_test 20.2 {
  WITH c(i)AS(VALUES(5)UNIoN SELECT 0)SELECT min(1)-i fROM c;
} {1}

# 2018-12-26
# Two different CTE tables with the same name appear in within a single FROM
# clause due to the query-flattener optimization.  make sure this does not cause
# problems.  This problem was discovered by Matt Denton.
#
do_execsql_test 21.1 {
   WITH RECURSIVE t21(a,b) AS (
    WITH t21(x) AS (VALUES(1))
    SELECT x, x FROM t21 ORDER BY 1
  )
  SELECT * FROM t21 AS tA, t21 AS tB
} {1 1 1 1}
do_execsql_test 21.2 {
  SELECT printf('',
     EXISTS (WITH RECURSIVE Table0 AS (WITH Table0 AS (SELECT DISTINCT 1)
                                       SELECT *, * FROM Table0 ORDER BY 1 DESC)
             SELECT * FROM Table0  NATURAL JOIN  Table0));
} {{}}

finish_test