Steps to replicate the issue (include links if applicable):

• Sometimes, page definitions generates by the "visual mode to edit the pagelist" generates page definitions that are not properly handled by the <pagelist/> tag. This happens if there is large number of such definitions and when they are not defined in sequence, eg. in this revision:

https://pl.wikisource.org/w/index.php?title=Indeks:PL_X_de_Mont%C3%A9pin_Zemsta_za_zemst%C4%99.djvu&oldid=3569732
page numbering definitions from page 603 are ignored.

What happens?:
some page numbering definitions are ignored

What should have happened instead?:
all page numbering definitions entered using this tool should be properly handled by the <pagelist /> tag.

Other information (browser name/version, screenshots, etc.):
It is unclear to me whether the bug is in the <pagelist/> handling code in ProofreadPage or in the visual mode tool that generates unsorted list of page definitions. Probably both. However, sorting the page numbering definitions manually to set them in the ascending order fixes the problem in this index page:
https://pl.wikisource.org/w/index.php?title=Indeks:PL_X_de_Mont%C3%A9pin_Zemsta_za_zemst%C4%99.djvu&oldid=3569870