[mangahere] page-reverse results in TypeError: 'generator' object is not reversible

[kattjevfel]

When trying to use extractor.mangahere.page-reverse=true, gallery-dl throws an error for each page instead, like this:

[gallery-dl][debug] Version 1.23.0-dev
[gallery-dl][debug] Python 3.10.5 - Linux-5.18.14-zen1-1-zen-x86_64-with-glibc2.35
[gallery-dl][debug] requests 2.27.1 - urllib3 1.26.9
[gallery-dl][debug] Starting DownloadJob for 'https://www.mangahere.cc/manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/'
[mangahere][debug] Using MangahereMangaExtractor for 'https://www.mangahere.cc/manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/'
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): www.mangahere.cc:443
[urllib3.connectionpool][debug] https://www.mangahere.cc:443 "GET /manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/ HTTP/1.1" 200 None
[mangahere][debug] Using MangahereChapterExtractor for 'https://www.mangahere.cc/manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/c001/1.html'
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): m.mangahere.cc:443
[urllib3.connectionpool][debug] https://m.mangahere.cc:443 "GET /manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/c001/1.html HTTP/1.1" 200 None
[urllib3.connectionpool][debug] https://www.mangahere.cc:443 "GET /manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/c001/ HTTP/1.1" 200 None
[mangahere][error] An unexpected error occurred: TypeError - 'generator' object is not reversible. Please run gallery-dl again with the --verbose flag, copy its output and report this issue on https://github.com/mikf/gallery-dl/issues .
[mangahere][debug] 
Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/gallery_dl/job.py", line 77, in run
    for msg in extractor:
  File "/usr/lib/python3.10/site-packages/gallery_dl/extractor/common.py", line 520, in items
    images = util.enumerate_reversed(imgs, 1, data["count"])
  File "/usr/lib/python3.10/site-packages/gallery_dl/util.py", line 169, in enumerate_reversed
    reversed(iterable),
TypeError: 'generator' object is not reversible

(cut after first page)

Can be reproduced with gallery-dl --verbose --ignore-config --option extractor.mangahere.page-reverse=true https://www.mangahere.cc/manga/an_evil_dragon_that_was_sealed_away_for_300_years_became_my_friend/

[mikf]

page-reverse currently only works for chapter extractors that return their results in one big list.

I can make it work for extractors that have to go page-by-page like mangahere, but that would mean the program sits around for several seconds/minutes doing "nothing" until it collected all pages.

Would that be OK? Because I really do not want to write code that actually goes through all website pages in reverse order.

[kattjevfel]

I use this feature so I can use --abort, but also not have it mess up with partially downloaded mangas. So having that solution versus none, I'll gladly take it.

Besides, I personally mainly use this application via a cronjob that runs as I sleep, and I can assure you I sleep for more than several seconds/minutes.

[mikf]

Fixed in commit dd3a6a9, but you might want to set a sleep-request value for mangahere. Otherwise gallery-dl will bombard the site with HTTP requests in a very unnatural way and might get you blocked.

[kattjevfel]

Seems to work for me, thanks!