SQLite

  int i;                          /* Iterator variable */
  int iCons = -1;                 /* Index of constraint to use */

  int iLangidCons = -1;           /* Index of langid=x constraint, if present */
  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
  int iIdx;

  if( p->bLock ){
    return SQLITE_ERROR;
  }

  /* By default use a full table scan. This is an expensive option,
  ** so search through the constraints to see if a more efficient 
  ** strategy is possible.
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 5000000;

    char *zSql;
    if( p->pSeekStmt ){
      pCsr->pStmt = p->pSeekStmt;
      p->pSeekStmt = 0;
    }else{
      zSql = sqlite3_mprintf("SELECT %s WHERE rowid = ?", p->zReadExprlist);
      if( !zSql ) return SQLITE_NOMEM;
      p->bLock++;
      rc = sqlite3_prepare_v3(
          p->db, zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0
      );
      p->bLock--;
      sqlite3_free(zSql);
    }
    if( rc==SQLITE_OK ) pCsr->bSeekStmt = 1;
  }
  return rc;
}

/*
** Position the pCsr->pStmt statement so that it is on the row
** of the %_content table that contains the last match.  Return
** SQLITE_OK on success.  
*/
static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
  int rc = SQLITE_OK;
  if( pCsr->isRequireSeek ){
    rc = fts3CursorSeekStmt(pCsr);
    if( rc==SQLITE_OK ){
      Fts3Table *pTab = (Fts3Table*)pCsr->base.pVtab;
      pTab->bLock++;
      sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
      pCsr->isRequireSeek = 0;
      if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
        pTab->bLock--;
        return SQLITE_OK;
      }else{
        pTab->bLock--;
        rc = sqlite3_reset(pCsr->pStmt);
        if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
          /* If no row was found and no error has occurred, then the %_content
          ** table is missing a row that is present in the full-text index.
          ** The data structures are corrupt.  */
          rc = FTS_CORRUPT_VTAB;
          pCsr->isEof = 1;

** even if we reach end-of-file.  The fts3EofMethod() will be called
** subsequently to determine whether or not an EOF was hit.
*/
static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){
  int rc;
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
  if( pCsr->eSearch==FTS3_DOCID_SEARCH || pCsr->eSearch==FTS3_FULLSCAN_SEARCH ){
    Fts3Table *pTab = (Fts3Table*)pCursor->pVtab;
    pTab->bLock++;
    if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){
      pCsr->isEof = 1;
      rc = sqlite3_reset(pCsr->pStmt);
    }else{
      pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);
      rc = SQLITE_OK;
    }
    pTab->bLock--;
  }else{
    rc = fts3EvalNext((Fts3Cursor *)pCursor);
  }
  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  return rc;
}

  sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */
  sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */
  sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */
  int iIdx;

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  if( p->bLock ){
    return SQLITE_ERROR;
  }

  eSearch = (idxNum & 0x0000FFFF);
  assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( p->pSegments==0 );

  /* Collect arguments into local variables */
  iIdx = 0;

      );
    }else{
      zSql = sqlite3_mprintf("SELECT %s ORDER BY rowid %s", 
          p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
      );
    }
    if( zSql ){
      p->bLock++;
      rc = sqlite3_prepare_v3(
          p->db,zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0
      );
      p->bLock--;
      sqlite3_free(zSql);
    }else{
      rc = SQLITE_NOMEM;
    }
  }else if( eSearch==FTS3_DOCID_SEARCH ){
    rc = fts3CursorSeekStmt(pCsr);
    if( rc==SQLITE_OK ){

  char **azColumn;                /* column names.  malloced */
  u8 *abNotindexed;               /* True for 'notindexed' columns */
  sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
  char *zContentTbl;              /* content=xxx option, or NULL */
  char *zLanguageid;              /* languageid=xxx option, or NULL */
  int nAutoincrmerge;             /* Value configured by 'automerge' */
  u32 nLeafAdd;                   /* Number of leaf blocks added this trans */
  int bLock;                      /* Used to prevent recursive content= tbls */

  /* Precompiled statements used by the implementation. Each of these 
  ** statements is run and reset within a single virtual table API call. 
  */
  sqlite3_stmt *aStmt[40];
  sqlite3_stmt *pSeekStmt;        /* Cache for fts3CursorSeekStmt() */

      }
  
      case FTS5_PLAN_SORTED_MATCH: {
        rc = fts5SorterNext(pCsr);
        break;
      }
  
      default: {
        Fts5Config *pConfig = ((Fts5Table*)pCursor->pVtab)->pConfig;
        pConfig->bLock++;
        rc = sqlite3_step(pCsr->pStmt);
        pConfig->bLock--;
        if( rc!=SQLITE_ROW ){
          CsrFlagSet(pCsr, FTS5CSR_EOF);
          rc = sqlite3_reset(pCsr->pStmt);
          if( rc!=SQLITE_OK ){
            pCursor->pVtab->zErrMsg = sqlite3_mprintf(
                "%s", sqlite3_errmsg(pConfig->db)
            );
          }
        }else{
          rc = SQLITE_OK;
        }
        break;
      }
    }
  }
  
  return rc;
}

  sqlite3_value *pRowidLe = 0;    /* rowid <= ? expression (or NULL) */
  sqlite3_value *pRowidGe = 0;    /* rowid >= ? expression (or NULL) */
  int iCol;                       /* Column on LHS of MATCH operator */
  char **pzErrmsg = pConfig->pzErrmsg;
  int i;
  int iIdxStr = 0;
  Fts5Expr *pExpr = 0;

  if( pConfig->bLock ){
    pTab->p.base.zErrMsg = sqlite3_mprintf(
        "recursively defined fts5 content table"
    );
    return SQLITE_ERROR;
  }

  if( pCsr->ePlan ){
    fts5FreeCursorComponents(pCsr);
    memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan-(u8*)pCsr));
  }

  assert( pCsr->pStmt==0 );

        pTab->pStorage, eStmt, &pCsr->pStmt, (bErrormsg?&pTab->p.base.zErrMsg:0)
    );
    assert( rc!=SQLITE_OK || pTab->p.base.zErrMsg==0 );
    assert( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_CONTENT) );
  }

  if( rc==SQLITE_OK && CsrFlagTest(pCsr, FTS5CSR_REQUIRE_CONTENT) ){
    Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
    assert( pCsr->pExpr );
    sqlite3_reset(pCsr->pStmt);
    sqlite3_bind_int64(pCsr->pStmt, 1, fts5CursorRowid(pCsr));
    pTab->pConfig->bLock++;
    rc = sqlite3_step(pCsr->pStmt);
    pTab->pConfig->bLock--;
    if( rc==SQLITE_ROW ){
      rc = SQLITE_OK;
      CsrFlagClear(pCsr, FTS5CSR_REQUIRE_CONTENT);
    }else{
      rc = sqlite3_reset(pCsr->pStmt);
      if( rc==SQLITE_OK ){
        rc = FTS5_CORRUPT;
      }else{
        pTab->base.zErrMsg = sqlite3_mprintf(
            "%s", sqlite3_errmsg(pTab->pConfig->db)
        );
      }
    }
  }
  return rc;
}

static void fts5SetVtabError(Fts5FullTable *p, const char *zFormat, ...){

  SELECT name FROM sqlite_master;
} {}

#---------------------------------------------------------------------------
# Check that an fts5 table cannot be its own content table.
#
reset_db
do_execsql_test 7.1.1 {
  CREATE VIRTUAL TABLE t1 USING fts5(a, c=t1 );
  INSERT INTO t1( a ) VALUES('abc');
}
do_catchsql_test 7.1.2 { 
  SELECT * FROM t1; 
} {1 {recursively defined fts5 content table}}
do_catchsql_test 7.1.3 { 
  SELECT * FROM t1('abc'); 
} {1 {recursively defined fts5 content table}}
do_catchsql_test 7.1.4 { 
  SELECT count(*) FROM t1;
} {1 {recursively defined fts5 content table}}
do_catchsql_test 7.1.5 { 
  SELECT * FROM t1('abc') ORDER BY rank;
} {1 {recursively defined fts5 content table}}

reset_db
do_execsql_test 7.2.1 {
  CREATE VIRTUAL TABLE t1 USING fts5(a, c=t2 );
  CREATE VIRTUAL TABLE t2 USING fts5(a, c=t1 );
  INSERT INTO t1( a ) VALUES('abc');
}
do_catchsql_test 7.2.2 { 
  SELECT * FROM t1; 
} {1 {recursively defined fts5 content table}}
do_catchsql_test 7.2.3 { 
  SELECT * FROM t1('abc'); 
} {1 {recursively defined fts5 content table}}
do_catchsql_test 7.2.4 { 
  SELECT count(*) FROM t1;
} {1 {recursively defined fts5 content table}}
do_catchsql_test 7.2.5 { 
  SELECT * FROM t1('abc') ORDER BY rank;
} {1 {recursively defined fts5 content table}}

finish_test

# Test cases 11.*
# 
reset_db

do_catchsql_test 11.1 {
  CREATE VIRTUAL TABLE x1 USING fts4(content=x1);
} {1 {vtable constructor called recursively: x1}}

#---------------------------------------------------------------------------
# Check that an fts4 table cannot be its own content table.
#
reset_db
breakpoint
do_execsql_test 12.1.1 {
  CREATE VIRTUAL TABLE t1 USING fts4(a, content=t1 );
  INSERT INTO t1(rowid, a) VALUES(1, 'abc');
}
do_catchsql_test 12.1.2 { 
  SELECT * FROM t1; 
} {1 {SQL logic error}}
do_catchsql_test 12.1.3 { 
  SELECT * FROM t1('abc'); 
} {1 {SQL logic error}}
do_catchsql_test 12.1.4 { 
  SELECT count(*) FROM t1;
} {1 {SQL logic error}}

reset_db
do_execsql_test 12.2.1 {
  CREATE VIRTUAL TABLE t1 USING fts4(a, content=t2 );
  CREATE VIRTUAL TABLE t2 USING fts4(a, content=t1 );
  INSERT INTO t1(rowid, a) VALUES(1, 'abc');
}
do_catchsql_test 12.2.2 { 
  SELECT * FROM t1; 
} {1 {SQL logic error}}
do_catchsql_test 12.2.3 { 
  SELECT * FROM t1('abc'); 
} {1 {SQL logic error}}
do_catchsql_test 12.2.4 { 
  SELECT count(*) FROM t1;
} {1 {SQL logic error}}



finish_test