Regression: Copilot Undo reverts git-committed changes (similar to #3492)

[tharveysa]

Does this issue occur when all extensions are disabled?: No - requires Copilot extension

• VS Code Version: 1.107.1
• OS Version: Windows 11

Steps to Reproduce:

1. Have Copilot (agent mode) edit File A (e.g., utils.ts)
2. Do NOT click "Keep" - instead, stage and commit File A via git directly
3. Push the commit to remote (git push)
4. Have Copilot edit File B (e.g., api.config.ts) - do NOT commit
5. Have Copilot edit File C (e.g., use-mobile.tsx) - do NOT commit
6. Click "Undo" on the Copilot edits
7. Dialog shows all files including File A (which was committed+pushed)
8. Click "Yes" to proceed with undo
9. File A is reverted, removing the COMMITTED changes

Result: Git now shows File A as modified - the pushed commit's content was removed by Undo.

Expected: File A should not be in the undo list at all since it was committed to git. Committing should clear the file from Copilot's undo tracking.

Workaround: Run git checkout HEAD -- <filename> to restore from commit.

Note: This appears to be a regression of microsoft/vscode-copilot-release#3492 which was marked fixed in March 2025.

[tharveysa]

Update - Additional reproduction details:

Reproduced the bug again with more details:

1. Keep/Undo panel showed "2 files changed"
2. Clicked Undo → confirmation dialog said "6 files" would be affected
3. After undo, a committed+pushed file (bc-api-client.ts) lost its committed content

The UI is inconsistent - the panel count doesn't match the dialog count, and neither accurately reflects what's actually being undone. Files from previous sessions/commits are being silently included in the undo operation.

[lszomoru]

@connor4312, is there API for the git extension to be able to do this?

[connor4312]

It sounds like basically the ask here is an auto-keep-on-commit feature. There is no API for that but I am not opposed to the idea.

@lszomoru what do you think the best shape for the API here is? I think we would have some notion of both files and ranges within those files, so that if parts of a file or changes were committed we don't incorrectly accept the entire file. If you want to propose something I can implement it in the edit session side.

[lszomoru]

@connor4312, couple of months ago I did implement auto-keep when staging/committing a resource that is in the working set of a chat session - #262885. Is there a chance that there is a bug or something missing in my implementation?

[connor4312]

The reporter says they "stage and commit File A via git directly" which implies using a terminal command, so I don't think that was covered by your previous work. We would just have to observe the state transition I guess here, which seems sketchier.

[lszomoru]

@tharveysa, could you please confirm that you have committed the change using the terminal?

@connor4312, the git extension already listens to onDidEndTerminalShellExecution in order to refresh the state of the SCM views in case a git command is being run in the integrated terminal. Having said that, I do agree that this is not that straightforward as we would have to understand which resources are impacted by the terminal command in order to remove them from the working set...

[tharveysa]

@lszomoru this is correct. It's done through the terminal by the agent.

[tharveysa]

To clarify the workflow - Copilot agent mode commits via terminal using commands like:

git add <file>
git commit -m "message"
git push

These are executed through the integrated terminal (via the agent's run_in_terminal tool or similar). The VS Code SCM UI is not involved at all.

So the issue is:

1. Agent edits File A → file enters "Keep/Undo" tracking
2. Agent runs git commit in terminal → file is committed but NOT removed from Keep/Undo tracking
3. Later, clicking "Undo" still includes File A, reverting the committed content

The fix would need to detect when a file in the Keep/Undo working set gets committed via terminal git commands, not just via the SCM UI.