Fix ChangeDocumentType not removing VBA parts when converting to non-macro type

[iamcymentho]

Summary

Fixes #618

When changing a macro-enabled document (.docm) to a standard document (.docx) via ChangeDocumentType(), VBA-related parts (VbaProjectPart, VbaDataPart, etc.) were carried over to the new document type unchanged. This left orphaned vbaProject content type entries in [Content_Types].xml, producing a file that:

• Could not be opened correctly by some tools
• Silently retained macro capabilities in a supposedly non-macro document

Changes

• TypedPackageFeatureCollection.cs — After ChangeDocumentTypeInternal completes, check if the new content type is non-macro-enabled. If so, remove parts with VBA relationship types (vbaProject, keyMapCustomizations) from the new main part.
• DocxTests01.cs — Added test that creates a .docm with a VbaProjectPart, converts it to .docx, and verifies:
  1. VbaProjectPart is null after conversion
  2. The vbaProject content type is absent from the package

Test results

Test Project	Total	Passed	Failed
DocumentFormat.OpenXml.Tests	2316	2313	0
DocumentFormat.OpenXml.Framework.Tests	192	192	0
DocumentFormat.OpenXml.Packaging.Tests	190	190	0

Test plan

• New test ChangeDocumentType_MacroEnabledToDocument_RemovesVbaParts passes
• All 3 existing ChangeDocumentType tests still pass
• Full test suite (2698 tests) passes with 0 failures

[iamcymentho]

@dotnet-policy-service agree

[github-actions]

Test Results

    68 files  ± 0      68 suites  ±0   1h 42m 33s ⏱️ + 5m 8s
 2 069 tests + 1   2 066 ✅ + 1   3 💤 ±0  0 ❌ ±0 
38 050 runs   - 16  38 008 ✅  - 16  42 💤 ±0  0 ❌ ±0 

Results for commit b50732c. ± Comparison against base commit 3ee250c.

♻️ This comment has been updated with latest results.

[iamcymentho]

Thanks for the feedback @twsouthwick @mikeebowen! I've reworked the implementation:

• Moved VBA cleanup out of the shared TypedPackageFeatureCollection into WordprocessingDocumentFeatures
• Added a virtual OnDocumentTypeChanged hook in the base class so each document type can handle its own cleanup
• Replaced the HashSet + LINQ approach with direct DeletePartsOfType<VbaProjectPart>() and DeletePartsOfType<CustomizationPart>() calls , no LINQ, no extra using
• Uses enum pattern matching (is MacroEnabledDocument or MacroEnabledTemplate) instead of string checks

If Excel/PowerPoint need the same treatment, their feature classes can override OnDocumentTypeChanged independently.

[Copilot]

Pull request overview

Fixes Word ChangeDocumentType() conversion from macro-enabled (.docm) to non-macro (.docx/.dotx) by adding a post-conversion cleanup hook and using it to remove VBA-related parts after the main part content type is switched (addresses #618).

Changes:

• Add a generic OnDocumentTypeChanged(...) hook to TypedPackageFeatureCollection and invoke it after ChangeDocumentTypeInternal.
• Override the hook for WordprocessingDocument to delete VbaProjectPart and CustomizationPart when converting to non-macro types.
• Add a test that creates a .docm, converts to .docx, and asserts VBA parts are removed.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
test/DocumentFormat.OpenXml.Tests/DocxTests01.cs	Adds coverage for .docm → .docx conversion and VBA removal assertions.
src/DocumentFormat.OpenXml/Packaging/WordprocessingDocument.cs	Implements Word-specific cleanup after document type changes to non-macro types.
src/DocumentFormat.OpenXml/Packaging/TypedPackageFeatureCollection.cs	Introduces and calls a post-document-type-change hook for typed package feature collections.

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[iamcymentho]

@twsouthwick @mikeebowen Friendly follow-up, this is a reminder about latest push which addresses all review feedback. The only open question is whether to extend the VBA cleanup to Excel/PowerPoint in this PR or a separate one. Happy to proceed either way once you've had a chance to align.