Last page is not remembered for files with more than 1500 pages

[fvictorio]

Distribution

Linux Mint 22.1 Xia

Package version

4.2.6

Frequency

Always

Bug description

If a PDF has more than 1500 pages, then the last page you read is not remembered.

Steps to reproduce

I'm attaching two PDF files: one with 1500 empty pages and one with 1501.

1. Open the file with 1501 pages.
2. Scroll to the second page.
3. Close xreader.
4. Open the file again.

xreader opens the file at the first page. This doesn't happen if you do the same with the file with 1500 pages.

out1500.pdf
out1501.pdf

Expected behavior

The last page I read should be remembered, no matter how many pages the file has.

Additional information

If I open the file with 1501 pages from the terminal, I see this error when I close the file:

(xreader:3173652): Gtk-CRITICAL **: 12:31:32.369: gtk_widget_get_visible: assertion 'GTK_IS_WIDGET (widget)' failed

Another hint that might be relevant is this line:

xreader/shell/ev-sidebar-thumbnails.c

Line 50 in 4682832

#define MAX_ICON_VIEW_PAGE_COUNT 1500

It seems like an "IconView" is not created when the file has more than 1500 pages, which might be the root cause of the problem (or not, what do I know).

[jaeheonshim]

I think I've managed to identify the issue. When the file has more than 1500 pages, a TreeView is used instead of an IconView. There is an event handler on the TreeView for when the user changes the selection so that the page can be set. However, when the list backing the TreeView was being cleared row by row, this event handler was also triggered, causing the page number to be incorrectly updated when the user closes the document.

PR: #694