[release/9.0-staging] Fix IsOSVersionAtLeast when build or revision are not provided

[github-actions]

Backport of #108748 to release/9.0-staging

/cc @kotlarmilos

Customer Impact

• Customer reported
• Found internally

This PR fixes #108694 by updating IsOSVersionAtLeast to treat unspecified build or revision components as zero. Previously, the IsOSVersionAtLeast didn't normalize components, leading to incorrect version checks on MacCatalyst when only two components (major and minor) were provided.

Regression

• Yes
• No

On MacCatalyst, the version does not include build or revision components, and tests only covered the four-parameter overload of IsOSVersionAtLeast.

Testing

The OperatingSystem tests have been extended to cover the three- and two-parameter overloads of IsOSVersionAtLeast.

Risk

Low. Only MacCatalyst should be affected, as it is the only platform that does not provide a build component. Also, this change does not introduce a breaking change.

[jeffhandley]

This looks good to me for servicing.

This fix targets only the IsOSVersionAtLeast so that it returns the expected value when a version.Build or version.Revision contains a value less than 0. That is different from the original fix in #108748 where the OperatingSystem instance itself is normalized to have 0 for those properties.

[jeffhandley]

@artl93 This is ready for Servicing now

[artl93]

Thanks! I'd like, to get clearer on the customer scenario for my education.

What does the app see right now? Is the problem that version checks apps do to, for example, make their code selectable based on versions of macOS work properly? How long has MacCatalyst worked this way?

[kotlarmilos]

What does the app see right now? Is the problem that version checks apps do to, for example, make their code selectable based on versions of macOS work properly?

This issue doesn’t make the code selectable based on different versions but leads to incorrect behavior.

For example, on MacCatalyst, if the version is set to 18.0 , it appears as 18.0.-1.-1. In this case, OperatingSystem.IsMacCatalystVersionAtLeast(18,0) would return false, since it compared a default build component (0) with the OS-provided build component (-1).

How long has MacCatalyst worked this way?

We have no evidence that iOSSupportVersion in SupportVersion.plist has ever included build or revision components.