fix(fuse): a file deleted just as its create lands is trashed on Drive (B173)

docs/BUGS.md

@@ -12,6 +12,28 @@ Conventions:
 
 ---
 
+## B173 — A file deleted just as its create lands stays on Drive
+
+**Status:** Fixed (unverified).
+**Found:** 2026-10-04, by `one_client_on_a_good_link` (seed 12) on d850265, run three at a time
+in a loop: one of nine runs failed. A deleted `c.bin` was still on Drive with its old bytes,
+and the next `c.bin` made on the mount landed as a conflict copy beside it.
+
+**Where:** `trash_child` in `crates/pdfs-fuse/src/filesystem.rs`.
+
+**Cause.** When a create lands, the drain retires its op and moves the node's row to the uid
+Drive gave it, then gives the tree that uid. In between, it caches the uploaded bytes. A delete
+in that gap still found the file under its stand-in, found no op left to drop, and took it for
+a file Drive had never seen. So nothing trashed it on Drive.
+
+**Fix.** After dropping a stand-in's ops, the delete checks whether the node's row has a real
+uid. If it has, the create landed first, and the file is trashed on Drive like any other.
+
+**Test:** `a_file_deleted_as_its_create_lands_is_trashed_on_drive` in
+`crates/pdfs-fuse/src/sim/daemon.rs`, which holds the drain between the two steps.
+
+---
+
 ## B172 — A file renamed while its upload is read back shows its old name
 
 **Status:** Fixed (unverified).

docs/CHANGELOG.md

@@ -72,6 +72,8 @@ by its local id, in the queue, the stored tree and pins alike.
   it failed with "Input/output error" (B170).
 - **A file deleted while its upload was retrying is removed from Drive right away.** It no
   longer waits for the upload's next retry (B171).
+- **A file deleted just as it reached Drive is removed from Drive too.** It no longer stayed
+  there, and the next file with that name no longer became a conflict copy (B173).
 - **A file renamed just as its upload finished keeps its new name.** The mount no longer showed
   the old name, and a second rename no longer failed with "No such file or directory" (B152,
   B172).

docs/MILESTONE-3.0.0-STATUS.md

@@ -9,7 +9,7 @@ Tracks `docs/MILESTONE-3.0.0.md`. Update it with every commit that moves a phase
 - **Phase 2**: local ids, inode = local id, one tree for every mount (2.10.0).
 - **Phase 3, first part**: mkdir, create, rename, unlink and rmdir on the mount are recorded
   locally and sent from the queue; `"local_first": false` brings back the old path (5e0f30c).
-- Fixes from the simulation and account runs since then: B127 and B141 to B172.
+- Fixes from the simulation and account runs since then: B127 and B141 to B173.
 - **Sync issues, first cut** (§6.2): refusals sorted into issues, shown at once in the app,
   tray and CLI; Export button and `pdfs sync export`; `pdfs sync issues`.
 
@@ -115,7 +115,9 @@ Tracks `docs/MILESTONE-3.0.0.md`. Update it with every commit that moves a phase
          it replaced as its base, and the next write failed with `EIO` (B170, fixed). The
          suite's seed 9 found a deleted file's trash waiting out its create's backoff (B171,
          fixed). Run three at a time on 2502af6, seed 8 failed two of nine runs: a file renamed
-         while its upload was read back showed its old name again (B172, fixed).
+         while its upload was read back showed its old name again (B172, fixed). The loop
+         on d850265 failed seed 12 once in nine runs: a file deleted just as its create
+         landed stayed on Drive (B173, fixed).
 5. **Release**: 2.10.0 is tagged; the 2.9.0 tag still waits for the user's go-ahead.
 
 ## After 3.0.0