Downloading favicon for book is not working for Apple (iOS/macOS)

[BPerlakiH]

On Kiwix Apple, we are using the libkiwix function to get the image data for the books, like so:

https://github.com/kiwix/kiwix-apple/blob/820869b2d9ddc40f88b6ed1f9f4a0bd3f0de128a/Model/Entities/ZimFileMetaData/ZimFileMetaData.mm#L159-L170

Unfortunately for all books, this function comes back with an error, and no data is returned.
We fall into the catch block here:

libkiwix/src/book.cpp

Line 244 in 610b8cb

std::cerr << "Cannot download favicon from " << url;

I am not sure if it's Apple only specific, but it's consistently failing for every book, that we just fetched from the catalog.

[rgaudin]

@BPerlakiH is this related to that old ticket? kiwix/kiwix-apple#789 (comment)

[BPerlakiH]

@rgaudin Yes it seems so, it is the very same function that we are referring to.

[kelson42]

@veloman-yunkan Is this function working at all? tested properly?

[veloman-yunkan]

@kelson42 I don't think that it is tested properly. I see a potential issue with it when the illustration's URL points to a redirected address (I don't consider the obvious silly case when the favicon's URL is plain wrong).

We fall into the catch block here:

libkiwix/src/book.cpp

Line 244 in 610b8cb

std::cerr << "Cannot download favicon from " << url;

Does this debugging statement work? Does it print the problematic URL? Is the resource at that URL accessible? What is the HTTP response to a GET request to that URL?

[kelson42]

@BPerlakiH Please share the detail for a failing example so we get a chance to fix the bug. This is a priority.

[BPerlakiH]

This is the message we get back on the console:

Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/3511345c-4221-d9dd-23d8-60e88335d77f/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/0d17fed5-29f0-a0f0-4c7b-867450270337/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/1d66634a-510d-2c69-0def-9a0e942c1904/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/4d116654-e346-5b27-9dbe-f4cbac2f98e7/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/36b01178-ee2b-e96f-9e96-0aee09cdce19/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/5cdfea60-726b-03c8-4a6e-1e18392af505/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/9178576f-9bc4-ba73-abe1-cd9c83881a21/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/18d09afb-88c2-1c1d-31ba-992ec59f6beb/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/f7199730-8153-357c-d302-d9f3baf0f357/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/6e6211db-63a1-52eb-8554-340f7af9795f/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/c43c593d-006e-538d-621e-a67cd2227d5f/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/1901a4d3-29b0-0f07-26d7-94d849f3d883/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/2e9bcc9f-420a-fa75-73cd-c322d445c089/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/40dcb30d-56c3-238c-d1b2-6d7d89d929bc/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/7d493deb-2f5c-8f0a-56e1-43d66e418238/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/cc525677-62fb-554e-5f94-0574126baf03/?size=48Cannot download favicon from https://library.kiwix.org/catalog/v2/illustration/5798dc0f-b0e6-da75-53d9-d991cd6933ff/?size=48

and the list goes on..

If I parse out the urls:

https://library.kiwix.org/catalog/v2/illustration/3511345c-4221-d9dd-23d8-60e88335d77f/?size=48
https://library.kiwix.org/catalog/v2/illustration/0d17fed5-29f0-a0f0-4c7b-867450270337/?size=48
https://library.kiwix.org/catalog/v2/illustration/1d66634a-510d-2c69-0def-9a0e942c1904/?size=48
https://library.kiwix.org/catalog/v2/illustration/4d116654-e346-5b27-9dbe-f4cbac2f98e7/?size=48
https://library.kiwix.org/catalog/v2/illustration/36b01178-ee2b-e96f-9e96-0aee09cdce19/?size=48
https://library.kiwix.org/catalog/v2/illustration/5cdfea60-726b-03c8-4a6e-1e18392af505/?size=48
https://library.kiwix.org/catalog/v2/illustration/9178576f-9bc4-ba73-abe1-cd9c83881a21/?size=48
https://library.kiwix.org/catalog/v2/illustration/18d09afb-88c2-1c1d-31ba-992ec59f6beb/?size=48
https://library.kiwix.org/catalog/v2/illustration/f7199730-8153-357c-d302-d9f3baf0f357/?size=48
https://library.kiwix.org/catalog/v2/illustration/6e6211db-63a1-52eb-8554-340f7af9795f/?size=48
https://library.kiwix.org/catalog/v2/illustration/c43c593d-006e-538d-621e-a67cd2227d5f/?size=48
https://library.kiwix.org/catalog/v2/illustration/1901a4d3-29b0-0f07-26d7-94d849f3d883/?size=48
https://library.kiwix.org/catalog/v2/illustration/2e9bcc9f-420a-fa75-73cd-c322d445c089/?size=48
https://library.kiwix.org/catalog/v2/illustration/40dcb30d-56c3-238c-d1b2-6d7d89d929bc/?size=48
https://library.kiwix.org/catalog/v2/illustration/7d493deb-2f5c-8f0a-56e1-43d66e418238/?size=48
https://library.kiwix.org/catalog/v2/illustration/cc525677-62fb-554e-5f94-0574126baf03/?size=48
https://library.kiwix.org/catalog/v2/illustration/5798dc0f-b0e6-da75-53d9-d991cd6933ff/?size=48

each of those can be opened in browser (or otherwise), and the HTTP response is 200.

[veloman-yunkan]

The problem was that our build of libcurl didn't support HTTPS protocol. A fix (or, at least, part of it) is in kiwix/kiwix-build#807