Steps to Reproduce

1. load the zul with the file
2. scroll down the sheet with a steady speed.
see keikai-624.mp4

Current Result

zss.wpd:18352 Uncaught TypeError: Cannot read properties of undefined (reading 'appendZSH')
at init.appendZSH (zss.wpd:18352:61)
at init._appendZSH (zss.wpd:40514:20)
at init._setRowHeight (zss.wpd:40567:10)
at init._setRowHeight (zssex.wpd:4247:33)
at init.updateRowAutoHeight (zssex.wpd:4832:15)
at init.fireProcessAutoHeight_ (zssex.wpd:4880:33)
at init.create_ (zss.wpd:18327:10)
at init.$supers (zk.wpd:11639:21)
at init.create_ (zss.wpd:25206:9)
at init._createCellsIfCached (zss.wpd:25241:10)

Expected Result

no error

Debug Information

• the js error is caused by:
  the last row in this.rows (CellBlockCtrl.rows) doesn't match the row index, this.rows[143].r is 145, it should be 143.
  this.rows[this.rows.length-1].r != row.r-1
  I found that's because this.rows doesn't contain serial rows, there are 2 rows missing in the middle, e.g.
  rows[300].r=300
  rows[301].r=303

• when scrolling down, keikai will append each row's widget and DOM:

  appendRow (zss.wpd:18620)
  create_ (zss.wpd:18299)
  $supers (zk.wpd:11639)
  create_ (zss.wpd:25206)
  _createCellsIfCached (zss.wpd:25241)
  doScroll (zss.wpd:25344)
  _doScroll (zss.wpd:35965)
  _doVScroll (zss.wpd:35959)
  (anonymous) (zss.wpd:35946)
  

After appending rows, it will set auto row height

_setRowHeight (zss.wpd:40761)
_setRowHeight (zssex.wpd:4247)
updateRowAutoHeight (zssex.wpd:4832)
fireProcessAutoHeight_ (zssex.wpd:4880)
create_ (zss.wpd:18327)
$supers (zk.wpd:11639)
create_ (zss.wpd:25206)
_createCellsIfCached (zss.wpd:25241)
doScroll (zss.wpd:25344)
_doScroll (zss.wpd:35965)
_doVScroll (zss.wpd:35959)

MainBlockCtrl

	_createCellsIfCached: function (dir, size, jump, vr0) {
		var sheet = this.sheet,
			wgt = sheet._wgt,
			cr = this.range,
			...
		switch (dir) {
		case 'south':
			var tRow = Math.max(cr.bottom + 1, sheet.tp.block ? sheet.tp.block.range.bottom + 1 : 0),

When the error happens, cr.bottom is 1 more than actually rendered row index. .e.g. cr.bottom is 300, but currently keikai only renders to the row index 299. So tRow will be 301. Then 301-299 = 2, so there are 2 rows not appended.

the range.bottom is changed by

_setRowHeight: function(row, height, fireevent, loadvis, hidden, metaid, isCustom) {
...
		let visitBottom = zss.SSheetCtrl._getVisibleRange(this).bottom;
		if (this.getSheetData().rect.bottom >= visitBottom) {
			...
			this.activeBlock.range.bottom = visitBottom;
			this.activeBlock.range.reCalcSize();
		}

this.activeBlock.range.bottom = visitBottom; usually set the range.bottom to a number 1 more than this.activeBlock.range.bottom but there is no row appended actually. It will cause appending row incorrectly in _createCellsIfCached().

Workaround

don't change this.activeBlock.range.bottom in _setRowHeight().