Fix abandoned COM activation lifetime

[Gordon Lam (yeelam-gordon)]

Summary

• give exact -Embedding startup a bounded five-second window-handoff lease
• cancel the lease for restored or newly created windows, including reentrant initialization and queued WM_TIMER races
• preserve normal final-window exit and explicit AllowHeadless behavior without coupling lifetime to COM object counts
• add packaged COM/process lifecycle coverage and release-checklist mappings C246-C248

This replaces #22 with a fix aligned to the current classic COM architecture. Orphaned wtcli listen client cleanup remains a separate focused follow-up because subscriptions intentionally do not own Terminal process lifetime.

Validation

• cmd.exe /c "tools\razzle.cmd && cd src\cascadia\WindowsTerminal && bx"
• x64 Debug CascadiaPackage build and deployment
• Feature.Packaging.Tests.ps1 against the deployed Dev package: 17 passed, 0 failed, 5 expected winapp-dependent skips
• release report: C246, C247, and C248 checked

[Copilot]

Pull request overview

This PR fixes a WindowsTerminal COM local-server activation edge case where a -Embedding-launched process could linger indefinitely (blocking MSIX upgrades), by adding a bounded startup “handoff lease” that exits if no real window is created—while preserving existing “final window closed” behavior and respecting AllowHeadless.

Changes:

• Added a 5-second -Embedding startup timer in WindowEmperor and ensured it’s safely canceled/neutralized during window creation (including message-pump/reentrancy races).
• Added packaged E2E coverage for abandoned activation exit, valid handoff survival, and explicit headless survival.
• Updated E2E suite documentation and release checklist mappings for the new coverage items (C246–C248).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/cascadia/WindowsTerminal/WindowEmperor.h	Adds handoff timer ID constant and a counter to guard against reentrant window-creation races.
src/cascadia/WindowsTerminal/WindowEmperor.cpp	Implements the 5s -Embedding handoff lease, cancels it on window creation, and handles the timer message safely.
test/e2e/tests/Feature.Packaging.Tests.ps1	Adds 3 E2E tests validating the COM activation lifetime behavior (abandoned, valid handoff, AllowHeadless).
test/e2e/ItE2E/Private/Paths.ps1	Adds helper to read the protocol COM CLSID from the installed package manifest.
test/e2e/ItE2E/ItE2E.psm1	Exports the new Get-ItProtocolComClsid helper for test use.
test/e2e/README.md	Updates suite description and case count to reflect new COM activation lifecycle tests.
doc/release-check-list.md	Adds new checklist items C246–C248 mapped to the new E2E coverage.

[github-actions]

check-spelling-bot Report

⚠️ Dictionary not found

Problems were encountered retrieving check dictionaries (cspell:swift/src/swift.txt cspell:public-licenses/src/additional-licenses.txt cspell:java/src/java-terms.txt cspell:cpp/src/people.txt cspell:python/src/python/python.txt cspell:scala/dict/scala.txt cspell:docker/src/docker-words.txt cspell:cpp/src/compiler-msvc.txt cspell:python/src/common/extra.txt cspell:sql/src/sql.txt cspell:clojure/src/clojure.txt cspell:node/dict/node.txt cspell:cpp/src/compiler-gcc.txt cspell:software-terms/dict/softwareTerms.txt cspell:k8s/dict/k8s.txt cspell:cpp/src/stdlib-c.txt cspell:python/src/python/python-lib.txt cspell:cpp/src/lang-jargon.txt cspell:rust/dict/rust.txt cspell:sql/src/tsql.txt cspell:gaming-terms/dict/gaming-terms.txt cspell:cpp/src/stdlib-cerrno.txt cspell:python/src/additional_words.txt cspell:django/dict/django.txt cspell:fullstack/dict/fullstack.txt cspell:typescript/dict/typescript.txt cspell:golang/dict/go.txt cspell:java/src/java.txt cspell:software-terms/dict/webServices.txt cspell:haskell/dict/haskell.txt cspell:svelte/dict/svelte.txt cspell:cpp/src/stdlib-cpp.txt cspell:php/dict/php.txt cspell:cpp/src/stdlib-cmath.txt cspell:r/src/r.txt cspell:npm/dict/npm.txt cspell:cpp/src/compiler-clang-attributes.txt cspell:shell/dict/shell-all-words.txt cspell:monkeyc/src/monkeyc_keywords.txt cspell:dotnet/dict/dotnet.txt cspell:css/dict/css.txt cspell:public-licenses/src/generated/public-licenses.txt cspell:dart/src/dart.txt cspell:lua/dict/lua.txt cspell:elixir/dict/elixir.txt cspell:powershell/dict/powershell.txt cspell:ruby/dict/ruby.txt cspell:html/dict/html.txt cspell:cpp/src/ecosystem.txt cspell:cpp/src/template-strings.txt cspell:cpp/src/lang-keywords.txt cspell:redis/dict/redis.txt cspell:latex/dict/latex.txt cspell:ada/dict/ada.txt).

⚠️ For more information, see check-dictionary-not-found.

🔴 Please review

See the 📂 files view, the 📜action log, 👼 SARIF report, or 📝 job summary for details.

Unrecognized words (1)

DCOM

These words are not needed and should be removed

AHP aiu Backgrounder CANTCALLOUT Ccc cplusplus ctl Debian depl dotnet drv endptr EOFs evt frob frobnicate Fullwidth gitlab hdr idl IME inbox ININPUTSYNCCALL INJ intelligentterminal Ioctl KVM lbl lld lsb NODEFAULT NONINFRINGEMENT notif oss outdir Podcast pri prioritization rcv segfault SND sourced SWP Tbl testname transitioning unk unparseable unregisters Virt VMs webpage websites WINVER WSLENV xsi

To accept these unrecognized words as correct and remove the previously acknowledged and now absent words, you could run the following commands

... in a clone of the git@github.com:microsoft/intelligent-terminal.git repository
on the dev/yeelam/reliability/embedding-handoff-timeout branch (ℹ️ how do I use this?):

curl -s -S -L 'https://raw.githubusercontent.com/check-spelling/check-spelling/cfb6f7e75bbfc89c71eaa30366d0c166f1bd9c8c/apply.pl' |
perl - 'https://github.com/microsoft/intelligent-terminal/actions/runs/31071040758/attempts/1' &&
git commit -m 'Update check-spelling metadata'

Available 📚 dictionaries could cover words (expected and unrecognized) not in the 📘 dictionary

This includes both expected items (2100) from .github/actions/spelling/expect/alphabet.txt .github/actions/spelling/expect/expect.txt .github/actions/spelling/expect/web.txt and unrecognized words (1)

Dictionary	Entries	Covers	Uniquely
cspell:csharp/csharp.txt	32	2	2
cspell:aws/aws.txt	232	2	2
cspell:fonts/fonts.txt	536	1	1

Consider adding to the extra_dictionaries array (in the .github/actions/spelling/config.json file):

    "cspell:csharp/csharp.txt",
    "cspell:aws/aws.txt",
    "cspell:fonts/fonts.txt",

To stop checking additional dictionaries, put (in the .github/actions/spelling/config.json file):

"check_extra_dictionaries": []

Pattern suggestions ✂️ (1)

You could add these patterns to .github/actions/spelling/patterns/55cd53b0bcb5da6ba5fa83c5d891ebab76c5d45d.txt:

# Automatically suggested patterns

# hit-count: 1 file-count: 1
# container images
image: [-\w./:@]+

Alternatively, if a pattern suggestion doesn't make sense for this project, add a # to the beginning of the line in the candidates file with the pattern to stop suggesting it.

Warnings and Notices ⚠️ (2)

See the 📂 files view, the 📜action log, 👼 SARIF report, or 📝 job summary for details.

⚠️ Warnings and Notices	Count
ℹ️ candidate-pattern	1
⚠️ check-dictionary-not-found	53

See ⚠️ Event descriptions for more information.

✏️ Contributor please read this

By default the command suggestion will generate a file named based on your commit. That's generally ok as long as you add the file to your commit. Someone can reorganize it later.

If the listed items are:

• ... misspelled, then please correct them instead of using the command.
• ... names, please add them to .github/actions/spelling/allow/names.txt.
• ... APIs, you can add them to a file in .github/actions/spelling/allow/.
• ... just things you're using, please add them to an appropriate file in .github/actions/spelling/expect/.
• ... tokens you only need in one place and shouldn't generally be used, you can add an item in an appropriate file in .github/actions/spelling/patterns/.

See the README.md in each directory for more information.

🔬 You can test your commits without appending to a PR by creating a new branch with that extra change and pushing it to your fork. The check-spelling action will run in response to your push -- it doesn't require an open pull request. By using such a branch, you can limit the number of typos your peers see you make. 😉

If the flagged items are 🤯 false positives

If items relate to a ...

• binary file (or some other file you wouldn't want to check at all).

  Please add a file path to the excludes.txt file matching the containing file.

  File paths are Perl 5 Regular Expressions - you can test yours before committing to verify it will match your files.

  ^ refers to the file's path from the root of the repository, so ^README\.md$ would exclude README.md (on whichever branch you're using).

• well-formed pattern.

  If you can write a pattern that would match it,
  try adding it to the patterns.txt file.

  Patterns are Perl 5 Regular Expressions - you can test yours before committing to verify it will match your lines.

  Note that patterns can't match multiline strings.