Support mysql2 0.4.x and 0.5.x

[sodabrew]

Resolves #31636 following release of mysql2 0.5.0 today.

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[matthewd]

You probably want to change this too:

rails/railties/lib/rails/generators/app_base.rb

Line 302 in 89bcca5

when "mysql" then ["mysql2", ["~> 0.4.4"]]

I guess this diff tells me you at least read my comment, so that's nice 🤷‍♂️

[sodabrew]

Thanks I will add that change, too!

[Edouard-chin]

Should this be backported to 5-2-stable? Otherwise mysql2 0.5.0 will be only usable on Rails 6.0

[kamipo]

Yeah, I will do that.

[rafaelfranca]

And 5-1-stable too

[kamipo]

Backported in 6965f2a and 6a11d83.

[pixeltrix]

@kamipo doesn't 6965f2a need to be in 5-2-stable? It's currently in 5-2-0 only (@rafaelfranca what's the policy here - backport to 5-2-stable and then cherry-pick what we want in 5-2-0 or backport to 5-2-0 and then that'll be merged into 5-2-stable at some point?)

[matthewd]

5-2-0 will merge to 5-2-stable on release, so yeah seems fine to backport straight to there if we know it's post-rc-worthy

[kamipo]

Yeah, I supposed that 5-2-0 will be merged to 5-2-stable since db7edd8 is missing in 5-2-stable yet, and I needed the commit to add CHANGELOG entry 3eadd23.

[hkdnet]

It looks that 5-0-stable also needs this patch, right?
The head of 5-0-stable does not pass the ci.
https://travis-ci.org/rails/rails/builds/357081953

[jaredbeck]

And 5-1-stable too

Thanks for backporting ❤️

It looks that 5-0-stable also needs this patch, right?

If I understand correctly, 5.0 only receives security patches now (2018-03-23), and as soon as 5.2 is released, 5.0 will be EoL.

[pixeltrix]

I've backported this and the dalli fix to 5-0-stable and 4-2-stable just to be on the safe side - they're still used in a lot of apps so we at least want the build to be green should the worst happen and we have to release new gems for a major security issue.