Bug 306673 – [ITP] Crash in ResourceLoadStatisticsStore::ensureResourceStatisticsForRegistrableDomain due to unsafe std::optional access

• Status: RESOLVED
• Resolution: FIXED
• Component: Website Storage

[David Kilzer (:ddkilzer)]

ResourceLoadStatisticsStore::ensureResourceStatisticsForRegistrableDomain() crashes with `std::bad_optional_access` when calling `.value()` on an empty `std::optional<unsigned>` returned by `domainID(domain)`.

The crash occurs when:
1. `insertObservedDomain()` successfully inserts a domain into the database
2. `domainID(domain)` immediately fails to find the just-inserted domain, returning `std::nullopt`  
3. Calling `.value()` on the empty optional throws `std::bad_optional_access`
4. C++ runtime calls `abort()`, terminating the process

Stack trace:
```
0   libsystem_c.dylib:  abort
1   libc++.1.dylib:  std::bad_optional_access
2   libc++.1.dylib:  std::optional<unsigned>::value
3   WebKit:  WebKit::ResourceLoadStatisticsStore::domainID
4   WebKit:  WebKit::ResourceLoadStatisticsStore::insertObservedDomain
5   WebKit:  WebKit::ResourceLoadStatisticsStore::ensureResourceStatisticsForRegistrableDomain
6   WebKit:  WebKit::ResourceLoadStatisticsStore::setIsScheduledForAllScriptWrittenStorageRemoval
[...]
```

<rdar://167532652>

[David Kilzer (:ddkilzer)]

The fix replaces the unsafe `.value()` call with proper optional checking and error recovery. Also fixes a misleading error message.

Testing notes: Unable to write a test since it would require removing a just-inserted domain from the database using an unknown mechanism external to ensureResourceStatisticsForRegistrableDomain().

No change in behavior for successful operations, only improves error handling for edge cases.

[David Kilzer (:ddkilzer)]

Pull request: https://github.com/WebKit/WebKit/pull/57608

[EWS]

Committed 306672@main (215b7246a621): <https://commits.webkit.org/306672@main>

Reviewed commits have been landed. Closing PR #57608 and removing active labels.