SQLite

    rc = sqlite3_step(pSelect);
    if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect);
  }

  return rc;
}

/*
** This function is called from within sqlite3changset_apply_v2() when
** a conflict is encountered and resolved using conflict resolution
** mode eType (either SQLITE_CHANGESET_OMIT or SQLITE_CHANGESET_REPLACE)..
** It adds a conflict resolution record to the buffer in 
** SessionApplyCtx.rebase, which will eventually be returned to the caller
** of apply_v2() as the "rebase" buffer.
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise.
*/
static int sessionRebaseAdd(
  SessionApplyCtx *p, 
  int eType, 
  sqlite3_changeset_iter *pIter
  SessionApplyCtx *p,             /* Apply context */
  int eType,                      /* Conflict resolution (OMIT or REPLACE) */
  sqlite3_changeset_iter *pIter   /* Iterator pointing at current change */
){
  int rc = SQLITE_OK;
  int i;
  int eOp = pIter->op;
  if( p->bRebaseStarted==0 ){
    /* Append a table-header to the rebase buffer */
    const char *zTab = pIter->zTab;

  sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */
  sqlite3_free((char*)sApply.constraints.aBuf);
  sqlite3_free((char*)sApply.rebase.aBuf);
  sqlite3_mutex_leave(sqlite3_db_mutex(db));
  return rc;
}

/*
** Apply the changeset passed via pChangeset/nChangeset to the main 
** database attached to handle "db".
*/
int sqlite3changeset_apply_v2(
  sqlite3 *db,                    /* Apply change to "main" db of this handle */
  int nChangeset,                 /* Size of changeset in bytes */
  void *pChangeset,               /* Changeset blob */
  int(*xFilter)(
    void *pCtx,                   /* Copy of sixth arg to _apply() */
    const char *zTab              /* Table name */

struct sqlite3_rebaser {
  sqlite3_changegroup grp;        /* Hash table */
};

/*
** Buffers a1 and a2 must both contain a sessions module record nCol
** fields in size. This function appends an nCol sessions module 
** record to buffer pBuf that is a copy of a1, except that:
** record to buffer pBuf that is a copy of a1, except that for
**
**   + If bUndefined is 0, for each field that is not "undefined" in either
**     a1[] or a2[], swap in the field from a2[].
** each field that is undefined in a1[], swap in the field from a2[].
**
**   + If bUndefined is 1, for each field that is "undefined" in a1[]
**     swap in the field from a2[].
*/
static void sessionAppendRecordMerge(
  SessionBuffer *pBuf,
  int nCol,
  SessionBuffer *pBuf,            /* Buffer to append to */
  int nCol,                       /* Number of columns in each record */
  int bUndefined,
  u8 *a1, int n1,
  u8 *a2, int n2,
  int *pRc
  u8 *a1, int n1,                 /* Record 1 */
  u8 *a2, int n2,                 /* Record 2 */
  int *pRc                        /* IN/OUT: error code */
){
  sessionBufferGrow(pBuf, n1+n2, pRc);
  if( *pRc==SQLITE_OK ){
    int i;
    u8 *pOut = &pBuf->aBuf[pBuf->nBuf];
    for(i=0; i<nCol; i++){
      int nn1 = sessionSerialLen(a1);
      int nn2 = sessionSerialLen(a2);
      if( bUndefined==0 ){
        if( *a1 && *a2 ){
          memcpy(pOut, a2, nn2);
          pOut += nn2;
        }else{
          memcpy(pOut, a1, nn1);
          pOut += nn1;
        }
      }else{
        if( *a1==0 || *a1==0xFF ){
          memcpy(pOut, a2, nn2);
          pOut += nn2;
        }else{
          memcpy(pOut, a1, nn1);
          pOut += nn1;
      if( *a1==0 || *a1==0xFF ){
        memcpy(pOut, a2, nn2);
        pOut += nn2;
      }else{
        memcpy(pOut, a1, nn1);
        pOut += nn1;
        }
      }
      a1 += nn1;
      a2 += nn2;
    }

    pBuf->nBuf = pOut-pBuf->aBuf;
    assert( pBuf->nBuf<=pBuf->nAlloc );

          bDone = 1;
          if( pChange->op==SQLITE_DELETE ){
            if( pChange->bIndirect==0 ){
              u8 *pCsr = aRec;
              sessionSkipRecord(&pCsr, pIter->nCol);
              sessionAppendByte(&sOut, SQLITE_INSERT, &rc);
              sessionAppendByte(&sOut, pIter->bIndirect, &rc);
              sessionAppendRecordMerge(&sOut, pIter->nCol, 1,
              sessionAppendRecordMerge(&sOut, pIter->nCol,
                  pCsr, nRec-(pCsr-aRec), 
                  pChange->aRecord, pChange->nRecord, &rc
              );
            }
          }else{
            sessionAppendPartialUpdate(&sOut, pIter,
                aRec, nRec, pChange->aRecord, pChange->nRecord, &rc
            );
          }
          break;

        default:
          assert( pIter->op==SQLITE_DELETE );
          bDone = 1;
          if( pChange->op==SQLITE_INSERT ){
            sessionAppendByte(&sOut, SQLITE_DELETE, &rc);
            sessionAppendByte(&sOut, pIter->bIndirect, &rc);
            sessionAppendRecordMerge(&sOut, pIter->nCol, 1,
            sessionAppendRecordMerge(&sOut, pIter->nCol,
                pChange->aRecord, pChange->nRecord, aRec, nRec, &rc
            );
          }
          break;
      }
    }