function recordMintReservesFor(uint256 _tierId, uint256 _count)
  external
  override
  returns (uint256[] memory tokenIds)
{
  // Get a reference to the tier.
  JBStored721Tier storage _storedTier = _storedTierOf[msg.sender][_tierId];
  // Get a reference to the number of reserved tokens mintable for the tier.
  uint256 _numberOfReservedTokensOutstanding = _numberOfReservedTokensOutstandingFor(
    msg.sender,
    _tierId,
    _storedTier
  );
  if (_count > _numberOfReservedTokensOutstanding) revert INSUFFICIENT_RESERVES();
  ...
  for (uint256 _i; _i < _count; ) {
  // Generate the tokens.
  tokenIds[_i] = _generateTokenId(
    _tierId,
    _storedTier.initialQuantity - --_storedTier.remainingQuantity + _numberOfBurnedFromTier
  );
  unchecked {
    ++_i;
  }
}
function _numberOfReservedTokensOutstandingFor(
  address _nft,
  uint256 _tierId,
  JBStored721Tier memory _storedTier
) internal view returns (uint256) {
  // Invalid tier or no reserved rate?
  if (_storedTier.initialQuantity == 0 || _storedTier.reservedRate == 0) return 0;
  // No token minted yet? Round up to 1.
  // ******************* BUG HERE *********************
  if (_storedTier.initialQuantity == _storedTier.remainingQuantity) return 1;
  ...
}
