Recently, I found out that the Remove iOS-only NSUserDefaults-backed UA override commit is included in the WebKit version 616.1.27, which is going into iOS 17. As a result, I noticed some unexpected behavior in the user agent value when building iOS 17 with Xcode 15.
However, what's strange is that when I run a build built with Xcode 14.3 on iOS 17, there are no abnormal behaviors caused by the user agent.
I am aware that system frameworks like WebKit are dynamic frameworks. Therefore, if this commit is included in the WebKit version used in iOS 17, I expected the user agent to have an impact when running a build created with Xcode 14.3 on iOS 17 as well.
Why does it seem like the behavior of WebKit used in iOS 17 works when built with Xcode 15 but not when built with Xcode 14.3?
I used to understand that system frameworks like WebKit are built into iOS by default, and when my app record symbols as dynamic frameworks, app can later invoke functions from the embedded library when running the code. Consequently, I believed that even without updating the old build, as long as the iOS version is upgraded, app can automatically use the updated version of functions!
Is this understanding incorrect?