[Bug]: FilterVisibility strips visibility decorators

[dvv]

Describe the bug

Applying FilterVisibility strips visibility decorators from the resulting Model.
How to keep them for further filtering?
TIA

Reproduction

using Reflection;

@defaultVisibility(Marker.none)
internal enum Marker {
  none,
  filter,
  order,
  link,
}

internal model GuessListType<Type extends Model> { ...FilterVisibility<Type, #{ all: #[Lifecycle.Read], none: #[Marker.link] }, "{name}List"> }
internal model GuessOrderType<Type extends Model> { ...FilterVisibility<Type, #{ all: #[Marker.order] }, "{name}Order"> }

model Foo {
  @visibility(Marker.filter) @visibility(Marker.order) @visibility(Lifecycle.Read) @key id: string,
  @visibility(Marker.filter) @visibility(Marker.order) prop: int32,
  @visibility(Marker.link) links: int32[],
}

model FooList is GuessListType<Foo> {} // CORRECT: id, prop
model FooOrder is GuessOrderType<FooList> {} // INCORRECT: empty, should be id, prop

Checklist

• Follow our Code of Conduct
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.

[github-actions]

🎯 Issue Triage

FilterVisibility appears to remove visibility metadata from properties in the transformed model, so a second visibility filter cannot select properties that matched multiple markers on the source model.

Category: Bug
Area: compiler:core

🔗 [Playground Reproduction]((typespec.io/redacted)

📋 Reproduction code

using Reflection;

@defaultVisibility(Marker.none)
internal enum Marker {
  none,
  filter,
  order,
  link,
}

internal model GuessListType { ...FilterVisibility }
internal model GuessOrderType { ...FilterVisibility }

model Foo {
  @visibility(Marker.filter) @visibility(Marker.order) @visibility(Lifecycle.Read) @key id: string,
  @visibility(Marker.filter) @visibility(Marker.order) prop: int32,
  @visibility(Marker.link) links: int32[],
}

model FooList is GuessListType {} // CORRECT: id, prop
model FooOrder is GuessOrderType {} // INCORRECT: empty, should be prop

🔍 Analysis

This affects the compiler's standard-library reflection visibility transformation. The first FilterVisibility invocation correctly selects id and prop, but the resulting properties apparently no longer expose their original Marker.order visibility to the second invocation. The likely fault is in how applyVisibilityFilter materializes transformed model properties or carries visibility state forward.

#11036 concerns filtering inherited properties, while #7334 concerned nested-model reuse with the deprecated @withVisibilityFilter; neither describes this same chained-filter metadata loss.

📝 Suggested next steps

• Confirm whether preserving visibility metadata across FilterVisibility transformations is intended.
• Add a compiler test that applies two filters sequentially to properties with multiple custom visibility markers.
• Preserve the source visibility state on transformed properties if chained filtering is intended.

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