Finalize all cached vec0 stmts on commit (fixes #295)

vec0Sync only finalized stmtLatestChunk and the four stmtRowids* stmts.
The IVF/DiskANN/vectors stmts persisted on the vtab until xDisconnect,
which blocked sqlite3_close() (non-v2) with SQLITE_BUSY — the original
mozStorage case from #295. The same leak also broke VACUUM with
"SQL statements in progress" after any DiskANN operation.

Switch vec0Sync to call vec0_free_resources, which already finalizes
the full cache. Also fix a latent bug: the DiskANN block in
vec0_free_resources was nested inside #if SQLITE_VEC_EXPERIMENTAL_IVF_ENABLE,
so in the default build (DiskANN on, IVF off) those finalizes were
unreachable even from xDisconnect/xDestroy. Split into two independent
#if guards.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: asg017

sqlite-vec.c

@@ -3695,13 +3695,15 @@ void vec0_free_resources(vec0_vtab *p) {
     sqlite3_finalize(p->stmtIvfRowidMapLookup[i]); p->stmtIvfRowidMapLookup[i] = NULL;
     sqlite3_finalize(p->stmtIvfRowidMapDelete[i]); p->stmtIvfRowidMapDelete[i] = NULL;
     sqlite3_finalize(p->stmtIvfCentroidsAll[i]); p->stmtIvfCentroidsAll[i] = NULL;
+  }
+#endif
 #if SQLITE_VEC_ENABLE_DISKANN
+  for (int i = 0; i < VEC0_MAX_VECTOR_COLUMNS; i++) {
     sqlite3_finalize(p->stmtDiskannNodeRead[i]); p->stmtDiskannNodeRead[i] = NULL;
     sqlite3_finalize(p->stmtDiskannNodeWrite[i]); p->stmtDiskannNodeWrite[i] = NULL;
     sqlite3_finalize(p->stmtDiskannNodeInsert[i]); p->stmtDiskannNodeInsert[i] = NULL;
     sqlite3_finalize(p->stmtVectorsRead[i]); p->stmtVectorsRead[i] = NULL;
     sqlite3_finalize(p->stmtVectorsInsert[i]); p->stmtVectorsInsert[i] = NULL;
-#endif
   }
 #endif
 }
@@ -10370,28 +10372,7 @@ static int vec0Begin(sqlite3_vtab *pVTab) {
   return SQLITE_OK;
 }
 static int vec0Sync(sqlite3_vtab *pVTab) {
-  UNUSED_PARAMETER(pVTab);
-  vec0_vtab *p = (vec0_vtab *)pVTab;
-  if (p->stmtLatestChunk) {
-    sqlite3_finalize(p->stmtLatestChunk);
-    p->stmtLatestChunk = NULL;
-  }
-  if (p->stmtRowidsInsertRowid) {
-    sqlite3_finalize(p->stmtRowidsInsertRowid);
-    p->stmtRowidsInsertRowid = NULL;
-  }
-  if (p->stmtRowidsInsertId) {
-    sqlite3_finalize(p->stmtRowidsInsertId);
-    p->stmtRowidsInsertId = NULL;
-  }
-  if (p->stmtRowidsUpdatePosition) {
-    sqlite3_finalize(p->stmtRowidsUpdatePosition);
-    p->stmtRowidsUpdatePosition = NULL;
-  }
-  if (p->stmtRowidsGetChunkPosition) {
-    sqlite3_finalize(p->stmtRowidsGetChunkPosition);
-    p->stmtRowidsGetChunkPosition = NULL;
-  }
+  vec0_free_resources((vec0_vtab *)pVTab);
   return SQLITE_OK;
 }
 static int vec0Commit(sqlite3_vtab *pVTab) {

tests/test-cache-finalize.py

@@ -0,0 +1,34 @@
+"""Regression tests for #295: vec0 must finalize cached prepared statements
+on every commit, not just the rowid subset.
+
+Before the fix, `vec0Sync` only finalized `stmtLatestChunk` and the four
+`stmtRowids*` stmts; the DiskANN/IVF/vectors-read stmts persisted on the
+vtab indefinitely. Symptom: VACUUM after any DiskANN operation failed with
+"SQL statements in progress" because the cached stmts kept the connection
+busy. (The same leak also caused `sqlite3_close()` non-v2 to return
+SQLITE_BUSY — the original Firefox case in issue #295.)
+
+A separate latent bug — the DiskANN finalize block in `vec0_free_resources`
+was nested inside `#if SQLITE_VEC_EXPERIMENTAL_IVF_ENABLE`, so even
+xDisconnect/xDestroy didn't finalize DiskANN stmts in the default build.
+"""
+from helpers import _f32
+
+
+def test_vacuum_after_diskann_inserts(db):
+    db.execute(
+        "create virtual table v using vec0("
+        "a float[8] indexed by diskann(neighbor_quantizer=binary))"
+    )
+    for i in range(1, 11):
+        db.execute("insert into v(rowid, a) values (?, ?)",
+                   (i, _f32([0.1 * i] * 8)))
+    db.commit()
+    db.execute("VACUUM")
+
+
+def test_vacuum_after_flat_inserts(db):
+    db.execute("create virtual table v using vec0(a float[2])")
+    db.execute("insert into v(rowid, a) values (1, ?)", (_f32([0.1, 0.2]),))
+    db.commit()
+    db.execute("VACUUM")