int aParent[GR_MAX_PARENT]; /* Array of parents.  0 element is primary .*/
  char *zBranch;              /* Branch name */

  GraphRow *pNext;            /* Next row down in the list of all rows */
  GraphRow *pPrev;            /* Previous row */
  
  int idx;                    /* Row index.  First is 1.  0 used for "none" */
  u8 isLeaf;                  /* True if no direct child nodes */
  u8 isDup;                   /* True if this is duplicate of a prior entry */
  int iRail;                  /* Which rail this check-in appears on. 0-based.*/
  int aiRaiser[GR_MAX_RAIL];  /* Raisers from this node to a higher row. */
  int bDescender;             /* Raiser from bottom of graph to here. */
  u32 mergeIn;                /* Merge in from other rails */
  int mergeOut;               /* Merge out to this rail */
  int mergeUpto;              /* Draw the merge rail up to this level */

  free(p->azBranch);
  free(p->apHash);
  free(p);
}

/*
** Insert a row into the hash table.  If there is already another
** row with the same rid, overwrite the prior entry if the overwrite
** flag is set.
*/
static void hashInsert(GraphContext *p, GraphRow *pRow, int overwrite){
  int h;
  h = pRow->rid % p->nHash;
  while( p->apHash[h] && p->apHash[h]->rid!=pRow->rid ){
    h++;
    if( h>=p->nHash ) h = 0;
  }
  if( p->apHash[h]==0 || overwrite ){
    p->apHash[h] = pRow;
  }
}

/*
** Look up the row with rid.
*/
static GraphRow *hashFind(GraphContext *p, int rid){
  int h = rid % p->nHash;

  return iBest;
}

/*
** Compute the complete graph
*/
void graph_finish(GraphContext *p, int omitDescenders){
  GraphRow *pRow, *pDesc, *pDup;
  int i;
  u32 mask;
  u32 inUse;

  if( p==0 || p->pFirst==0 || p->nErr ) return;

  /* Initialize all rows */
  p->nHash = p->nRow*2 + 1;
  p->apHash = safeMalloc( sizeof(p->apHash[0])*p->nHash );
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    if( pRow->pNext ) pRow->pNext->pPrev = pRow;
    pRow->iRail = -1;
    pRow->mergeOut = -1;
    if( (pDup = hashFind(p, pRow->rid))!=0 ){
      pDup->isDup = 1;
    }
    hashInsert(p, pRow, 1);
  }
  p->mxRail = -1;

  /* Purge merge-parents that are out-of-graph
  */
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    for(i=1; i<pRow->nParent; i++){

  /* Figure out which nodes have no direct children (children on
  ** the same rail).  Mark such nodes is isLeaf.
  */
  memset(p->apHash, 0, sizeof(p->apHash[0])*p->nHash);
  for(pRow=p->pLast; pRow; pRow=pRow->pPrev) pRow->isLeaf = 1;
  for(pRow=p->pLast; pRow; pRow=pRow->pPrev){
    GraphRow *pParent;
    hashInsert(p, pRow, 0);
    if( pRow->nParent>0
     && (pParent = hashFind(p, pRow->aParent[0]))!=0
     && pRow->zBranch==pParent->zBranch
    ){
      pParent->isLeaf = 0;
    }
  }

  */
  inUse = (1<<(p->mxRail+1))-1;
  for(pRow=p->pLast; pRow; pRow=pRow->pPrev){
    int parentRid;
    if( pRow->iRail>=0 ) continue;
    assert( pRow->nParent>0 );
    parentRid = pRow->aParent[0];
    pDesc = hashFind(p, parentRid);
    if( pDesc==0 ){
      /* Time skew */
      pRow->iRail = ++p->mxRail;
      pRow->railInUse = 1<<pRow->iRail;
      continue;
    }
    if( pDesc->aiRaiser[pDesc->iRail]==0 && pDesc->zBranch==pRow->zBranch ){