CircularList.onInsert/onDelete only fire on reflow currently

[Tyriar]

They should also fire when the sequences for inserting and deleting lines are triggered:

xterm.js/src/InputHandler.ts

Lines 921 to 980 in 91d1f97

	/**
	* CSI Ps L
	* Insert Ps Line(s) (default = 1) (IL).
	*/
	public insertLines(params: IParams): void {
	this._restrictCursor();
	let param = params.params[0] || 1;
	// make buffer local for faster access
	const buffer = this._bufferService.buffer;
	if (buffer.y > buffer.scrollBottom || buffer.y < buffer.scrollTop) {
	return;
	}
	const row: number = buffer.y + buffer.ybase;
	const scrollBottomRowsOffset = this._bufferService.rows - 1 - buffer.scrollBottom;
	const scrollBottomAbsolute = this._bufferService.rows - 1 + buffer.ybase - scrollBottomRowsOffset + 1;
	while (param--) {
	// test: echo -e '\e[44m\e[1L\e[0m'
	// blankLine(true) - xterm/linux behavior
	buffer.lines.splice(scrollBottomAbsolute - 1, 1);
	buffer.lines.splice(row, 0, buffer.getBlankLine(this._terminal.eraseAttrData()));
	}
	this._dirtyRowService.markRangeDirty(buffer.y, buffer.scrollBottom);
	buffer.x = 0; // see https://vt100.net/docs/vt220-rm/chapter4.html - vt220 only?
	}
	/**
	* CSI Ps M
	* Delete Ps Line(s) (default = 1) (DL).
	*/
	public deleteLines(params: IParams): void {
	this._restrictCursor();
	let param = params.params[0] || 1;
	// make buffer local for faster access
	const buffer = this._bufferService.buffer;
	if (buffer.y > buffer.scrollBottom || buffer.y < buffer.scrollTop) {
	return;
	}
	const row: number = buffer.y + buffer.ybase;
	let j: number;
	j = this._bufferService.rows - 1 - buffer.scrollBottom;
	j = this._bufferService.rows - 1 + buffer.ybase - j;
	while (param--) {
	// test: echo -e '\e[44m\e[1M\e[0m'
	// blankLine(true) - xterm/linux behavior
	buffer.lines.splice(row, 1);
	buffer.lines.splice(j, 0, buffer.getBlankLine(this._terminal.eraseAttrData()));
	}
	this._dirtyRowService.markRangeDirty(buffer.y, buffer.scrollBottom);
	buffer.x = 0; // see https://vt100.net/docs/vt220-rm/chapter4.html - vt220 only?
	}

That's done via CircularList.splice which only fires onTrim:

xterm.js/src/common/CircularList.ts

Lines 154 to 180 in bc9649b

	public splice(start: number, deleteCount: number, ...items: T[]): void {
	// Delete items
	if (deleteCount) {
	for (let i = start; i < this._length - deleteCount; i++) {
	this._array[this._getCyclicIndex(i)] = this._array[this._getCyclicIndex(i + deleteCount)];
	}
	this._length -= deleteCount;
	}
	// Add items
	for (let i = this._length - 1; i >= start; i--) {
	this._array[this._getCyclicIndex(i + items.length)] = this._array[this._getCyclicIndex(i)];
	}
	for (let i = 0; i < items.length; i++) {
	this._array[this._getCyclicIndex(start + i)] = items[i];
	}
	// Adjust length as needed
	if (this._length + items.length > this._maxLength) {
	const countToTrim = (this._length + items.length) - this._maxLength;
	this._startIndex += countToTrim;
	this._length = this._maxLength;
	this.onTrimEmitter.fire(countToTrim);
	} else {
	this._length += items.length;
	}
	}

We should write failing test cases where a marker is created, an insert/delete occurs and the marker's line is wrong (before the change) and see if the events fix it.

[Tyriar]

This is already done