Lang: feature flag init if needed

[paul-schaaf]

closes #1191

[armaniferrante]

Blocked by #1199, since I promised we'd do a v0.20.1 release :).

[paul-schaaf]

@armaniferrante any idea what might be causing the test to fail? Im not able to reproduce it locally.

[ceciEstErmat]

I use it to initialize escrows of mints "on demand". Let's say a user wants to escrow mint X if it is the first one to do so then it will create the program escrow token account for this mint else it would just use the token account.

I found that feature pretty handy ! Even tho is forces us to always pass the system programs and token program and mint account 🤔

[paul-schaaf]

you can still do that. The feature isnt gone. You just have to explicitly enable it

[arcticmatt]

maybe add some documentation about how to enable it on this PR?

[ceciEstErmat]

@arcticmatt do something like this in your cargo

[dependencies]
anchor-lang = {version = "0.23.0", features = ["init-if-needed"]}

[arcticmatt]

@ceciEstErmat thanks! is that any different than doing this?

[features]
init-if-needed = []