add CURLSSLBACKEND_ALL enum

[TedLyngmo]

[ssl]: add CURLSSLBACKEND_ALL enum for cleaner code and examples

This is to make code that now does (curl_sslbackend)-1 clearer
and easier to read:

/* list the available ones */
const curl_ssl_backend **list;
curl_global_sslset(CURLSSLBACKEND_ALL, NULL, &list);

[bagder]

Also, you did not update symbols-in-versions so test 1119 fails.

[TedLyngmo]

symbols-in-versions

Thanks! What will the next version be? 8.3.1?

[bagder]

Thanks! What will the next version be? 8.3.1?

We are fairly sure it will become 8.4.0 so I think you can use that.

[jay]

IMO curl_global_sslset(CURLSSLBACKEND_ALL, ... is confusing because it implies setting all backends. To me, it makes more sense as -1.

[bagder]

CURLSSLBACKEND_ALL

Yeah, maybe *_NONE instead?

[TedLyngmo]

CURLSSLBACKEND_ALL

Yeah, maybe *_NONE instead?

CURLSSLBACKEND_NONE is already defined to 0. I used _ALL because it seemed to fit into the documentation:

/* list the available ones */
const curl_ssl_backend **list;
curl_global_sslset((curl_sslbackend)-1, NULL, &list);

Perhaps _ALL_AVAILABLE would be better?

[bagder]

CURLSSLBACKEND_NONE is already defined to 0. I used _ALL because it seemed to fit into the documentation:

Oh right. But maybe we should then rather change the documentation to use *NONE instead of -1? As far as I can see, that gives the same result...

[TedLyngmo]

CURLSSLBACKEND_NONE is already defined to 0. I used _ALL because it seemed to fit into the documentation:

Oh right. But maybe we should then rather change the documentation to use *NONE instead of -1? As far as I can see, that gives the same result...

Ah, well, that would certainly be even easier if it indeed does the same thing :-) I'm a bit worried about this note in the man-page that I missed before:

The backend can also be specified via the name parameter for a case insensitive match (passing -1 as id). If both id and name are specified, the name will be ignored.

That seems to imply that -1 and 0 are different somehow, but I haven't found how.

I added #11909 as an alternative to this PR.

[TedLyngmo]

Since #11909 has been approved, this PR is meaningless. Closing.