Bug 279339
| Summary: | CanMakeCheckedPtrBase::operator== should only be used by subclass' defaulted overload | ||
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| Product: | WebKit | Reporter: | Gerald Squelart <g_squelart> |
| Component: | Web Template Framework | Assignee: | Gerald Squelart <g_squelart> |
| Status: | RESOLVED FIXED | ||
| Severity: | Normal | CC: | webkit-bug-importer |
| Priority: | P2 | Keywords: | InRadar |
| Version: | WebKit Nightly Build | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Bug Depends on: | 279330 | ||
| Bug Blocks: | 279399 | ||
Gerald Squelart
`CanMakeCheckedPtrBase::operator==` just returns true, so that a subclass can defaults its operator==, and that default will effectively not consider the base CanMakeCheckedPtrBase when comparing base&member data.
This creates a possible foot-gun, where a sub-class doesn't define any operator==, so comparing objects will directly call `CanMakeCheckedPtrBase::operator==` and always compare equal!
This was the case for a comparison of Node's, which bug 279330 fixed.
It would be best to prevent this class of issues in the future.
This will be done by adding an opt-in template parameter to CanMakeCheckedPtr and CanMakeThreadSafeCheckedPtr, such that either:
- A derived class that defaults its operator== can safely use CanMakeCheckedPtrBase::operator==, or
- Other derived classes (that don't provide their own operator==) will not incorrectly compare equal in all cases.
| Attachments | ||
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| Add attachment proposed patch, testcase, etc. |
Radar WebKit Bug Importer
<rdar://problem/135527745>
Gerald Squelart
Pull request: https://github.com/WebKit/WebKit/pull/33306
EWS
Committed 283341@main (dd2152442c41): <https://commits.webkit.org/283341@main>
Reviewed commits have been landed. Closing PR #33306 and removing active labels.