Change DirectoryNotFoundException binary serialization constructor to use GetValueNoThrow

[Copilot]

Replace the linear foreach scan over SerializationInfo entries in DirectoryNotFoundException's deserialization constructor with a direct GetValueNoThrow lookup. Consistent other similar constructors in CoreLib..

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Pull request overview

Updates DirectoryNotFoundException binary deserialization to use SerializationInfo.GetValueNoThrow for the optional DirectoryPath field, aligning with patterns used by other exceptions and avoiding a linear scan over SerializationInfo entries.

Changes:

• Replace foreach (SerializationEntry ...) scan in the serialization constructor with a direct GetValueNoThrow lookup.

[github-actions]

Note

This review was generated by Copilot.

🤖 Copilot Code Review — PR #126648

Holistic Assessment

Motivation: The PR simplifies the DirectoryNotFoundException binary serialization constructor by replacing a manual foreach (SerializationEntry) loop with the existing SerializationInfo.GetValueNoThrow helper — a well-established internal API used by Exception, SecurityException, TimeZoneInfo.AdjustmentRule, and others for exactly this purpose. The cleanup is clearly justified.

Approach: This is the right approach. GetValueNoThrow does exactly what the manual loop did (find by name, return null if missing), and the codebase has no remaining foreach SerializationEntry patterns — this was the last one. The second commit correctly removes a superfluous comment at the maintainer's suggestion.

Summary: ✅ LGTM. A clean, one-line simplification that aligns with existing codebase patterns. No behavioral change, no new public API, no risk.

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Detailed Findings

✅ Correctness — Behavioral equivalence verified

The old code iterated entries looking for "DirectoryNotFound_DirectoryPath" and returned null if not found. GetValueNoThrow does the same via GetElementNoThrow → FindElement, returning null when the key is absent. Both paths cast the result to (string?). The only difference is GetValueNoThrow adds type-compatibility checking and converter fallback, which is strictly more robust (though irrelevant in practice since the value is serialized as typeof(string)).

✅ Consistency — Matches established pattern

All other optional-field deserialization sites use GetValueNoThrow:

• Exception.cs line 50 (Data)
• SecurityException.cs lines 60–65 (multiple fields)
• TimeZoneInfo.AdjustmentRule.cs lines 286, 292
• StringComparer.cs line 243

This change eliminates the last divergent pattern.

✅ No public API changes — No ref assembly impact

No changes to ref/ files. No new public members. The modified constructor is protected and [Obsolete] (legacy binary serialization). No API approval needed.

Generated by Code Review for issue #126648 · ◷

[jkotas]

@danmoseley Minor cleanup

[jkotas]

/ba-g trimming test failure is known issue #126675