docs: clarify behavior of sentry_flush + sentry_close

[sapphonie]

This PR

• clarifies that sentry_shutdown does not remove any crash handlers

Copying over a conversation from the Sentry discord;

supervacuus — Today at 4:25 AM
@sappho
The crashpad client does not provide a mechanism to uninstall its in-process crash-handler nor shutdown the crashpad_handler executable. So the handler is still installed after sentry_close().

On Linux we brutally restore signal handlers without making crashpad aware of this. Maybe we should do the same on Windows?

If you want to disable the crash-handler you can call SetUnhandledExceptionFilter(NULL) which will disable the local handler installed by crashpad. This can happen in your Shutdown() method right after invoking sentry_close().

More TODO involving

• documenting if sentry_flush() is async or not done, it is not async, it blocks
• documenting if sentry_close() is async or not done, see above
• documenting in example.c that crash handling will still be called after sentry_shutdown()

#skip-changelog

[codecov]

Codecov Report

Merging #883 (abfcb19) into master (d9e9019) will increase coverage by 6.24%.
The diff coverage is n/a.

❗ Current head abfcb19 differs from pull request most recent head 8d9115a. Consider uploading reports for the commit 8d9115a to get more accurate results

@@            Coverage Diff             @@
##           master     #883      +/-   ##
==========================================
+ Coverage   76.32%   82.56%   +6.24%     
==========================================
  Files          53       53              
  Lines        7366     7366              
  Branches     1185     1185              
==========================================
+ Hits         5622     6082     +460     
+ Misses       1195     1175      -20     
+ Partials      549      109     -440     

[supervacuus]

Thanks @sapphonie! Could you let me know if you're done with this PR? Is it okay if I take over and handle a few technicalities?

#skip-changelog

[sapphonie]

Thanks @sapphonie! Could you let me know if you're done with this PR? Is it okay if I take over and handle a few technicalities?

#skip-changelog

Sure, go ahead