HCELL_INDEX
CmpSplitLeaf(
      PHHIVE Hive,
      HCELL_INDEX RootCell,
      ULONG RootSelect,
      HSTORAGE_TYPE Type
  );

Routine Description:

    Split the Leaf index block specified by RootSelect, causing both
    of the split out Leaf blocks to appear in the Root index block
    specified by RootCell.

    Caller is expected to have marked old root cell dirty.

Arguments:

    Hive - pointer to hive control structure for hive of interest

    RootCell - cell of the Root index block of index being grown

    RootSelect - indicates which child of Root to split

    Type - Stable or Volatile

Return Value:

    HCELL_NIL - some resource problem

    Else - cell of new (e.g. reallocated) Root index block