More directly relevant to us in the present,
MuPDF 1.13 deals with it correctly.
Edit:
This seems to be by design; let's see why…
Code:
07/10/22-22:37:07 DEBUG BOGUS TOC: 32 3 < 31 25 - 28 29
07/10/22-22:37:07 DEBUG fix prev 31 25 => 1
07/10/22-22:37:07 DEBUG fix prev 30 22 => 1
07/10/22-22:37:07 DEBUG fix prev 29 21 => 1
07/10/22-22:37:07 DEBUG fix prev 28 21 => 1
07/10/22-22:37:07 DEBUG fix prev 27 21 => 1
07/10/22-22:37:07 DEBUG fix prev 26 20 => 1
07/10/22-22:37:07 DEBUG fix prev 25 19 => 1
07/10/22-22:37:07 DEBUG fix prev 24 18 => 1
07/10/22-22:37:07 DEBUG fix prev 23 17 => 1
07/10/22-22:37:07 DEBUG fix prev 22 15 => 1
07/10/22-22:37:07 DEBUG fix prev 21 15 => 1
07/10/22-22:37:07 DEBUG fix prev 20 15 => 1
07/10/22-22:37:07 DEBUG fix prev 19 14 => 1
07/10/22-22:37:07 DEBUG fix prev 18 14 => 1
07/10/22-22:37:07 DEBUG fix prev 17 13 => 1
07/10/22-22:37:07 DEBUG fix prev 16 12 => 1
07/10/22-22:37:07 DEBUG fix prev 15 12 => 1
07/10/22-22:37:07 DEBUG fix prev 14 11 => 1
07/10/22-22:37:07 DEBUG fix prev 13 9 => 1
07/10/22-22:37:07 DEBUG fix prev 12 9 => 1
07/10/22-22:37:07 DEBUG fix prev 11 8 => 1
07/10/22-22:37:07 DEBUG fix prev 10 8 => 1
07/10/22-22:37:07 DEBUG fix prev 9 7 => 1
07/10/22-22:37:07 DEBUG fix prev 8 7 => 1
07/10/22-22:37:07 DEBUG fix prev 7 6 => 1
07/10/22-22:37:07 DEBUG fix prev 6 5 => 1
07/10/22-22:37:07 DEBUG fix prev 5 5 => 1
07/10/22-22:37:07 DEBUG fix prev 4 5 => 1
Edit 2:
https://github.com/koreader/koreader/pull/5907
Edit 3:
https://github.com/koreader/koreader/issues/9319