[release/10.0] Fix LoadExactInterfaceMap for sub-interfaces with complex type arguments under special marker parents#124835
Open
github-actions[bot] wants to merge 4 commits intorelease/10.0from
Open
Conversation
…nts under special marker parents When pNewIntfMT is a special marker type and its sub-interface has an exact instantiation containing complex type arguments (e.g. IList(Of T) rather than bare T), the previous code would fall through to case 4 which checked EligibleForSpecialMarkerTypeUsage against pMT. This could incorrectly treat the sub-interface as an exact match when it still contains unresolved generic variables. Split old case 4 into three new cases: - Case 4: pNewIntfMT is a special marker type and the sub-interface's instantiation is eligible for special marker usage relative to pNewIntfMT (e.g. ILayer1(Of T) where T matches). Insert the marker. - Case 5: pNewIntfMT is a special marker type but the sub-interface has generic variables that don't match (e.g. ILayer1(Of IList(Of T))). Trigger retry with exact interfaces since full substitution is needed. - Case 6: The sub-interface is fully concrete or pNewIntfMT is not a special marker. Fall through to the existing pMT-based eligibility check. Add regression tests covering all 8 combinations of pre-loading the 3 interface layers. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
jkotas
approved these changes
Feb 25, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Backport of #124684 to release/10.0
/cc @davidwrighton
Customer Impact
[Select one or both of the boxes. Describe how this issue impacts customers, citing the expected and actual behaviors and scope of the issue. If customer-reported, provide the issue number.]
Regression
[If yes, specify when the regression was introduced. Provide the PR or commit if known.]
Testing
[How was the fix verified? How was the issue missed previously? What tests were added?]
Risk
[High/Medium/Low. Justify the indication by mentioning how risks were measured and addressed.]
IMPORTANT: If this backport is for a servicing release, please verify that:
release/X.0-staging, notrelease/X.0.release/X.0(no-stagingsuffix).Package authoring no longer needed in .NET 9
IMPORTANT: Starting with .NET 9, you no longer need to edit a NuGet package's csproj to enable building and bump the version.
Keep in mind that we still need package authoring in .NET 8 and older versions.