codeql/csharp/ql/lib/change-notes/2025-10-03-nullness.md

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• The representation of the C# control-flow graph has been significantly changed. This has minor effects on a wide range of queries including both minor improvements and minor regressions, for example, improved precision has been observed for cs/inefficient-containskey and cs/stringbuilder-creation-in-loop. Two queries stand out as being significantly affected with great improvements: cs/dereferenced-value-may-be-null has been completely rewritten which removes a very significant number of false positives. Furthermore, cs/constant-condition has been updated to report many new results - these new results are primarily expected to be true positives, but a few new false positives are expected as well. As part of these changes, cs/dereferenced-value-may-be-null has been changed from a path-problem query to a problem query, so paths are no longer reported for this query.