fix: Crash when Getting Subclasses

[philipphofmann]

📜 Description

Calling class_getSuperclass sometimes leads to EXC_I386_GPFLT. OneSignal
had the same issue OneSignal/OneSignal-iOS-SDK#278
and it was fixed with OneSignal/OneSignal-iOS-SDK#301.
This PR applies the changes they did to our code to fix the problem.

💡 Motivation and Context

Fixes GH-1395

💚 How did you test it?

Waiting for validation in GH-1395

📝 Checklist

• I reviewed the submitted code
• I added tests to verify the changes
• I updated the docs if needed
• Review from the native team if needed
• No breaking changes

🔮 Next steps

[Swatinem]

code lgtm, just not quite sure about the logic

[Swatinem]

I’m wondering when/if this condition can ever be reached?
According to the while loop above, superClass either needs to be nil or equal to parentClass to go over that. And above, you explicitly excluded the parentClass case, so I’m unsure what the code is supposed to do.

[brustolin]

The parentClass was excluded before the loop. But using class_getSuperclass we can get the parentClass again

[philipphofmann]

Good point @Swatinem. class_getSuperclass returns nil if the passed in class is a root class, like NSObject. Therefore, we need this check.

[brustolin]

Just wondering, what if we do the class image check here in the background minimizing the amount of classes in the indexesToSwizzle reducing code to run in the main thread later.

[philipphofmann]

Just wondering, what if we do the class image check here in the background minimizing the amount of classes in the indexesToSwizzle reducing code to run in the main thread later.

I'm not sure if I follow you here @brustolin. We do everything on a background thread except the swizzling.

[codecov-commenter]

Codecov Report

Merging #1396 (9d71b24) into master (e3ae241) will decrease coverage by 0.19%.
The diff coverage is 56.52%.

@@            Coverage Diff             @@
##           master    #1396      +/-   ##
==========================================
- Coverage   96.05%   95.86%   -0.20%     
==========================================
  Files         152      152              
  Lines        6747     6764      +17     
==========================================
+ Hits         6481     6484       +3     
- Misses        266      280      +14     

Impacted Files	Coverage Δ
Sources/Sentry/SentryUIViewControllerSwizziling.m	75.82% <56.52%> (-2.36%)	⬇️
Sources/Sentry/SentryRequestOperation.m	69.23% <0.00%> (-12.83%)	⬇️
Sources/Sentry/SentryInstallation.m	86.95% <0.00%> (-8.70%)	⬇️
Sources/Sentry/SentryNetworkTracker.m	99.41% <0.00%> (+0.58%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e3ae241...9d71b24. Read the comment docs.