fix(entry): guard LOCAL buffers from force-destroy in FileEntry:destroy

[dlyongemallo]

Motivated by #315 (comment).

[Copilot]

🟢 Approval recommended

The change is small, correctly scoped to guard LOCAL buffers, consistent with the existing created_bufs cleanup design, and fully covered by accurate tests with no issues found.

Pull request overview

This PR hardens buffer lifecycle handling in the diff scene by preventing FileEntry:destroy from force-deleting the user's real working-tree (LOCAL) buffers. Previously, refresh_files({ force = true }) (which reaches old_file:destroy(true) at diff_view.lua:860) would propagate force=true to every side of an entry, unconditionally deleting even LOCAL buffers — collapsing the tab the user opened from and losing its cursor position. The new force_for helper keeps forcing STAGE/COMMIT/CUSTOM virtual buffers (so their throwaway edits are still discarded) while downgrading LOCAL sides to the guarded force=false path. This is consistent with the existing separate cleanup of diffview-created LOCAL buffers via File.created_bufs in close().

Changes:

• Added a force_for(f) helper in FileEntry:destroy that only forwards force=true to non-LOCAL rev sides.
• Documented the rationale for guarding LOCAL buffers.
• Extended the destroy tests to cover mixed STAGE/LOCAL/COMMIT sides and the force=false pass-through case.

File summaries

File	Description
lua/diffview/scene/file_entry.lua	Introduces force_for so LOCAL files are never force-destroyed, with an explanatory doc comment.
lua/diffview/tests/functional/file_entry_spec.lua	Updates/adds tests asserting force is guarded for LOCAL and passed through unchanged when force=false.

I verified that the only destroy(true) caller is the force-refresh replace path (diff_view.lua:860), that RevType values match, that the helper logic and both tests are correct, and that LOCAL buffers created by diffview are still reaped separately via File.created_bufs, so this change does not leak buffers.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Balanced

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.