fix(fuse): a write closed just as its file's create lands is queued (B176)

docs/BUGS.md

@@ -12,6 +12,27 @@ Conventions:
 
 ---
 
+## B176 — A write closed just as its file's create lands is dropped
+
+**Status:** Fixed (unverified).
+**Found:** 2026-10-04, by `one_client_on_a_good_link` (seed 12) on 378667f, run three at a time
+in a loop. A write at offset 6 to a file whose create was landing never reached Drive; Drive
+ended with the file's first bytes and the later truncate only.
+
+**Where:** `Core::queue_revision` in `crates/pdfs-fuse/src/lib.rs`.
+
+**Cause.** A write handle closed on a file not yet on Drive first checks whether the create has
+landed and, if so, follows it to the uid Drive gave it. It then checks that the create is still
+queued; a file with neither was unlinked before it was created, and its write is dropped. A
+create that landed between the two checks looked like that, and the write was dropped.
+
+**Fix.** The landing removes the create op and gives the row its uid in one transaction. So a
+missing create op is checked against the row, and a landed file's write is queued for its uid.
+
+**Test:** `a_write_closed_as_its_create_lands_is_queued` in `crates/pdfs-fuse/src/lib.rs`.
+
+---
+
 ## B175 — A file replaced by a rename just as its create lands stays on Drive
 
 **Status:** Fixed (unverified).

docs/CHANGELOG.md

@@ -78,6 +78,7 @@ by its local id, in the queue, the stored tree and pins alike.
   (B174).
 - **A file replaced by a rename just as it reached Drive is removed from Drive too.** It no
   longer stayed there, and the next rename of its name no longer moved it instead (B175).
+- **A write closed just as its file reached Drive is no longer lost** (B176).
 - **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 B175.
+- Fixes from the simulation and account runs since then: B127 and B141 to B176.
 - **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`.
 
@@ -119,7 +119,8 @@ Tracks `docs/MILESTONE-3.0.0.md`. Update it with every commit that moves a phase
          on d850265 failed seed 12 once in nine runs: a file deleted just as its create
          landed stayed on Drive (B173, fixed). The suite on 378667f failed seed 6: a rename
          in the same gap was refused with `EACCES` (B174, fixed). The loop on 378667f failed
-         seed 8: a file replaced by a rename in that gap stayed on Drive (B175, fixed).
+         seed 8: a file replaced by a rename in that gap stayed on Drive (B175, fixed), and
+         seed 12: a write closed as its file's create landed was dropped (B176, 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