fix: reset metatable on filter change to remove stale metadata

cloudsync_set_filter and cloudsync_clear_filter now DELETE all rows from
the metatable and call cloudsync_refill_metatable after updating the
filter setting. This ensures the metatable only contains rows matching
the active filter, preventing stale non-matching rows from syncing.

Added SQL_DELETE_ALL_FROM_CLOUDSYNC_TABLE with platform-specific format
specifiers (%w for SQLite, %s for PostgreSQL) to avoid undefined
behavior from using SQLite's %w in PostgreSQL's vsnprintf.

Author: andinux

src/cloudsync.c

@@ -2528,6 +2528,18 @@ char *cloudsync_filter_add_row_prefix (const char *filter, const char *prefix, c
     return result;
 }
 
+int cloudsync_reset_metatable (cloudsync_context *data, const char *table_name) {
+    cloudsync_table_context *table = table_lookup(data, table_name);
+    if (!table) return DBRES_ERROR;
+
+    char *sql = cloudsync_memory_mprintf(SQL_DELETE_ALL_FROM_CLOUDSYNC_TABLE, table->meta_ref);
+    int rc = database_exec(data, sql);
+    cloudsync_memory_free(sql);
+    if (rc != DBRES_OK) return rc;
+
+    return cloudsync_refill_metatable(data, table_name);
+}
+
 int cloudsync_refill_metatable (cloudsync_context *data, const char *table_name) {
     cloudsync_table_context *table = table_lookup(data, table_name);
     if (!table) return DBRES_ERROR;

src/cloudsync.h

@@ -88,6 +88,8 @@ int    cloudsync_payload_get (cloudsync_context *data, char **blob, int *blob_si
 int    cloudsync_payload_save (cloudsync_context *data, const char *payload_path, int *blob_size); // available only on Desktop OS (no WASM, no mobile)
 
 // CloudSync table context
+int cloudsync_refill_metatable (cloudsync_context *data, const char *table_name);
+int cloudsync_reset_metatable (cloudsync_context *data, const char *table_name);
 cloudsync_table_context *table_lookup (cloudsync_context *data, const char *table_name);
 void *table_column_lookup (cloudsync_table_context *table, const char *col_name, bool is_merge, int *index);
 bool table_enabled (cloudsync_table_context *table);

src/postgresql/cloudsync_postgresql.c

@@ -686,6 +686,13 @@ Datum cloudsync_set_filter (PG_FUNCTION_ARGS) {
             ereport(ERROR, (errcode(ERRCODE_INTERNAL_ERROR),
                             errmsg("cloudsync_set_filter: error recreating triggers")));
         }
+
+        // Clean and refill metatable with the new filter
+        rc = cloudsync_reset_metatable(data, tbl);
+        if (rc != DBRES_OK) {
+            ereport(ERROR, (errcode(ERRCODE_INTERNAL_ERROR),
+                            errmsg("cloudsync_set_filter: error resetting metatable")));
+        }
     }
     PG_CATCH();
     {
@@ -744,6 +751,13 @@ Datum cloudsync_clear_filter (PG_FUNCTION_ARGS) {
             ereport(ERROR, (errcode(ERRCODE_INTERNAL_ERROR),
                             errmsg("cloudsync_clear_filter: error recreating triggers")));
         }
+
+        // Clean and refill metatable without filter (all rows)
+        rc = cloudsync_reset_metatable(data, tbl);
+        if (rc != DBRES_OK) {
+            ereport(ERROR, (errcode(ERRCODE_INTERNAL_ERROR),
+                            errmsg("cloudsync_clear_filter: error resetting metatable")));
+        }
     }
     PG_CATCH();
     {

src/postgresql/sql_postgresql.c

@@ -354,6 +354,9 @@ const char * const SQL_PRAGMA_TABLEINFO_LIST_NONPK_NAME_CID =
 const char * const SQL_DROP_CLOUDSYNC_TABLE =
     "DROP TABLE IF EXISTS %s CASCADE;";
 
+const char * const SQL_DELETE_ALL_FROM_CLOUDSYNC_TABLE =
+    "DELETE FROM %s;";
+
 const char * const SQL_CLOUDSYNC_DELETE_COLS_NOT_IN_SCHEMA_OR_PKCOL =
     "DELETE FROM %s WHERE col_name NOT IN ("
     "SELECT column_name FROM information_schema.columns WHERE table_name = '%s' "

src/sql.h

@@ -57,6 +57,7 @@ extern const char * const SQL_CLOUDSYNC_SELECT_COL_VERSION_BY_PK_COL;
 extern const char * const SQL_CLOUDSYNC_SELECT_SITE_ID_BY_PK_COL;
 extern const char * const SQL_PRAGMA_TABLEINFO_LIST_NONPK_NAME_CID;
 extern const char * const SQL_DROP_CLOUDSYNC_TABLE;
+extern const char * const SQL_DELETE_ALL_FROM_CLOUDSYNC_TABLE;
 extern const char * const SQL_CLOUDSYNC_DELETE_COLS_NOT_IN_SCHEMA_OR_PKCOL;
 extern const char * const SQL_PRAGMA_TABLEINFO_PK_QUALIFIED_COLLIST_FMT;
 extern const char * const SQL_CLOUDSYNC_GC_DELETE_ORPHANED_PK;

src/sqlite/cloudsync_sqlite.c

@@ -1259,6 +1259,14 @@ void dbsync_set_filter (sqlite3_context *context, int argc, sqlite3_value **argv
         return;
     }
 
+    // Clean and refill metatable with the new filter
+    rc = cloudsync_reset_metatable(data, tbl);
+    if (rc != DBRES_OK) {
+        dbsync_set_error(context, "cloudsync_set_filter: error resetting metatable");
+        sqlite3_result_error_code(context, rc);
+        return;
+    }
+
     sqlite3_result_int(context, 1);
 }
 
@@ -1289,6 +1297,14 @@ void dbsync_clear_filter (sqlite3_context *context, int argc, sqlite3_value **ar
         return;
     }
 
+    // Clean and refill metatable without filter (all rows)
+    rc = cloudsync_reset_metatable(data, tbl);
+    if (rc != DBRES_OK) {
+        dbsync_set_error(context, "cloudsync_clear_filter: error resetting metatable");
+        sqlite3_result_error_code(context, rc);
+        return;
+    }
+
     sqlite3_result_int(context, 1);
 }
 

src/sqlite/sql_sqlite.c

@@ -226,6 +226,9 @@ const char * const SQL_PRAGMA_TABLEINFO_LIST_NONPK_NAME_CID =
 const char * const SQL_DROP_CLOUDSYNC_TABLE =
     "DROP TABLE IF EXISTS \"%w\";";
 
+const char * const SQL_DELETE_ALL_FROM_CLOUDSYNC_TABLE =
+    "DELETE FROM \"%w\";";
+
 const char * const SQL_CLOUDSYNC_DELETE_COLS_NOT_IN_SCHEMA_OR_PKCOL =
     "DELETE FROM \"%w\" WHERE \"col_name\" NOT IN ("
     "SELECT name FROM pragma_table_info('%q') UNION SELECT '%s'"

test/postgresql/47_row_filter_advanced.sql

@@ -37,23 +37,24 @@ SELECT (:fail::int + 1) AS fail \gset
 -- Clear filter
 SELECT cloudsync_clear_filter('tasks') AS _cf \gset
 
--- Insert non-matching row — should now be tracked
+-- Insert non-matching row — should now be tracked (no filter)
+-- clear_filter refilled metatable with all 3 existing rows (a, b, c) + insert d = 4
 INSERT INTO tasks VALUES ('d', 'Task D', 2);
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM tasks_cloudsync \gset
-SELECT (:meta_pk_count = 3) AS clear_t1b_ok \gset
+SELECT (:meta_pk_count = 4) AS clear_t1b_ok \gset
 \if :clear_t1b_ok
-\echo [PASS] (:testid) clear_filter: non-matching row tracked after clear (3 PKs)
+\echo [PASS] (:testid) clear_filter: non-matching row tracked after clear (4 PKs)
 \else
-\echo [FAIL] (:testid) clear_filter: expected 3 PKs after clear+insert, got :meta_pk_count
+\echo [FAIL] (:testid) clear_filter: expected 4 PKs after clear+insert, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
--- Update previously-untracked row 'b' — should now be tracked
+-- Update row 'b' — already tracked by clear_filter refill, meta count unchanged
 UPDATE tasks SET title = 'Task B Updated' WHERE id = 'b';
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM tasks_cloudsync \gset
 SELECT (:meta_pk_count = 4) AS clear_t1c_ok \gset
 \if :clear_t1c_ok
-\echo [PASS] (:testid) clear_filter: update on 'b' tracked after clear (4 PKs)
+\echo [PASS] (:testid) clear_filter: update on 'b' still 4 PKs
 \else
 \echo [FAIL] (:testid) clear_filter: expected 4 PKs after update on 'b', got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
@@ -156,18 +157,19 @@ SELECT (:meta_count = 2) AS change_t6a_ok \gset
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
--- Change filter
+-- Change filter — resets metatable to only rows matching new filter (user_id = 2)
+-- Only 'b' (user_id=2) matches new filter → 1 PK from refill, then insert d → 2
 SELECT cloudsync_set_filter('fchange', 'user_id = 2') AS _sf2 \gset
 
 INSERT INTO fchange VALUES ('d', 'D', 2);  -- matches new filter
 INSERT INTO fchange VALUES ('e', 'E', 1);  -- non-matching under new filter
 
 SELECT COUNT(DISTINCT pk) AS meta_count FROM fchange_cloudsync \gset
-SELECT (:meta_count = 3) AS change_t6b_ok \gset
+SELECT (:meta_count = 2) AS change_t6b_ok \gset
 \if :change_t6b_ok
-\echo [PASS] (:testid) filter_change: 3 PKs after filter change (old metadata persists)
+\echo [PASS] (:testid) filter_change: 2 PKs after filter change (metatable reset)
 \else
-\echo [FAIL] (:testid) filter_change: expected 3 PKs after filter change, got :meta_count
+\echo [FAIL] (:testid) filter_change: expected 2 PKs after filter change, got :meta_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 

test/postgresql/49_row_filter_prefill.sql

@@ -35,16 +35,16 @@ SELECT cloudsync_init('tasks') AS _init_a \gset
 SELECT cloudsync_set_filter('tasks', 'user_id = 1') AS _sf_a \gset
 
 -- ============================================================
--- Test 1: Init refill should have created metadata for ALL 5 pre-existing rows
--- (filter was not set in settings when cloudsync_init ran the refill)
+-- Test 1: set_filter resets metatable to only matching rows
+-- cloudsync_init filled all 5, then set_filter cleaned and refilled → 3 matching (a, c, e)
 -- ============================================================
 
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM tasks_cloudsync \gset
-SELECT (:meta_pk_count = 5) AS prefill_t1_ok \gset
+SELECT (:meta_pk_count = 3) AS prefill_t1_ok \gset
 \if :prefill_t1_ok
-\echo [PASS] (:testid) prefill: all 5 pre-existing rows have metadata after init
+\echo [PASS] (:testid) prefill: 3 matching rows have metadata after set_filter
 \else
-\echo [FAIL] (:testid) prefill: expected 5 tracked PKs after init, got :meta_pk_count
+\echo [FAIL] (:testid) prefill: expected 3 tracked PKs after set_filter, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
@@ -54,11 +54,11 @@ SELECT (:fail::int + 1) AS fail \gset
 
 INSERT INTO tasks VALUES ('f', 'Task F', 1);
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM tasks_cloudsync \gset
-SELECT (:meta_pk_count = 6) AS prefill_t2_ok \gset
+SELECT (:meta_pk_count = 4) AS prefill_t2_ok \gset
 \if :prefill_t2_ok
-\echo [PASS] (:testid) prefill: new matching insert tracked (6 PKs)
+\echo [PASS] (:testid) prefill: new matching insert tracked (4 PKs)
 \else
-\echo [FAIL] (:testid) prefill: expected 6 PKs after matching insert, got :meta_pk_count
+\echo [FAIL] (:testid) prefill: expected 4 PKs after matching insert, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
@@ -68,11 +68,11 @@ SELECT (:fail::int + 1) AS fail \gset
 
 INSERT INTO tasks VALUES ('g', 'Task G', 2);
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM tasks_cloudsync \gset
-SELECT (:meta_pk_count = 6) AS prefill_t3_ok \gset
+SELECT (:meta_pk_count = 4) AS prefill_t3_ok \gset
 \if :prefill_t3_ok
-\echo [PASS] (:testid) prefill: new non-matching insert not tracked (still 6 PKs)
+\echo [PASS] (:testid) prefill: new non-matching insert not tracked (still 4 PKs)
 \else
-\echo [FAIL] (:testid) prefill: expected still 6 PKs after non-matching insert, got :meta_pk_count
+\echo [FAIL] (:testid) prefill: expected still 4 PKs after non-matching insert, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
@@ -99,13 +99,13 @@ SELECT cloudsync_set_filter('tasks', 'user_id = 1') AS _sf_b \gset
 -- Apply payload
 SELECT cloudsync_payload_apply(decode(:'payload_a_hex', 'hex')) AS _apply \gset
 
--- All pre-existing rows (a-e) + matching new (f) should arrive; non-matching new (g) should not
+-- Only matching rows (a, c, e, f) should arrive; non-matching (b, d, g) should not
 SELECT COUNT(*) AS row_count FROM tasks \gset
-SELECT (:row_count = 6) AS prefill_t4a_ok \gset
+SELECT (:row_count = 4) AS prefill_t4a_ok \gset
 \if :prefill_t4a_ok
-\echo [PASS] (:testid) prefill_sync: 6 rows synced to Database B
+\echo [PASS] (:testid) prefill_sync: 4 matching rows synced to Database B
 \else
-\echo [FAIL] (:testid) prefill_sync: expected 6 rows in Database B, got :row_count
+\echo [FAIL] (:testid) prefill_sync: expected 4 rows in Database B, got :row_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
@@ -119,13 +119,13 @@ SELECT (:g_count = 0) AS prefill_t4b_ok \gset
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
--- Verify pre-existing non-matching row 'b' DID sync (metadata from init refill)
+-- Verify pre-existing non-matching row 'b' did NOT sync (metadata removed by set_filter)
 SELECT COUNT(*) AS b_count FROM tasks WHERE id = 'b' AND user_id = 2 \gset
-SELECT (:b_count = 1) AS prefill_t4c_ok \gset
+SELECT (:b_count = 0) AS prefill_t4c_ok \gset
 \if :prefill_t4c_ok
-\echo [PASS] (:testid) prefill_sync: pre-existing non-matching row 'b' synced via refill
+\echo [PASS] (:testid) prefill_sync: pre-existing non-matching row 'b' not synced
 \else
-\echo [FAIL] (:testid) prefill_sync: pre-existing row 'b' should have synced via refill metadata
+\echo [FAIL] (:testid) prefill_sync: pre-existing non-matching row 'b' should not have synced
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
@@ -152,35 +152,35 @@ INSERT INTO projects VALUES (2, 2, 'Delta', 'active');
 SELECT cloudsync_init('projects') AS _init_proj \gset
 SELECT cloudsync_set_filter('projects', 'org_id = 1') AS _sf_proj \gset
 
--- All 4 pre-existing rows should have metadata
+-- set_filter resets metatable: only 2 matching rows (org_id=1) should have metadata
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM projects_cloudsync \gset
-SELECT (:meta_pk_count = 4) AS prefill_t5_ok \gset
+SELECT (:meta_pk_count = 2) AS prefill_t5_ok \gset
 \if :prefill_t5_ok
-\echo [PASS] (:testid) prefill_composite: all 4 pre-existing rows have metadata
+\echo [PASS] (:testid) prefill_composite: 2 matching rows have metadata after set_filter
 \else
-\echo [FAIL] (:testid) prefill_composite: expected 4 tracked PKs, got :meta_pk_count
+\echo [FAIL] (:testid) prefill_composite: expected 2 tracked PKs, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
 -- New matching insert tracked
 INSERT INTO projects VALUES (1, 3, 'Epsilon', 'active');
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM projects_cloudsync \gset
-SELECT (:meta_pk_count = 5) AS prefill_t5b_ok \gset
+SELECT (:meta_pk_count = 3) AS prefill_t5b_ok \gset
 \if :prefill_t5b_ok
-\echo [PASS] (:testid) prefill_composite: new matching row tracked (5 PKs)
+\echo [PASS] (:testid) prefill_composite: new matching row tracked (3 PKs)
 \else
-\echo [FAIL] (:testid) prefill_composite: expected 5 PKs after matching insert, got :meta_pk_count
+\echo [FAIL] (:testid) prefill_composite: expected 3 PKs after matching insert, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif
 
 -- New non-matching insert NOT tracked
 INSERT INTO projects VALUES (3, 1, 'Zeta', 'active');
 SELECT COUNT(DISTINCT pk) AS meta_pk_count FROM projects_cloudsync \gset
-SELECT (:meta_pk_count = 5) AS prefill_t5c_ok \gset
+SELECT (:meta_pk_count = 3) AS prefill_t5c_ok \gset
 \if :prefill_t5c_ok
-\echo [PASS] (:testid) prefill_composite: new non-matching row not tracked (still 5 PKs)
+\echo [PASS] (:testid) prefill_composite: new non-matching row not tracked (still 3 PKs)
 \else
-\echo [FAIL] (:testid) prefill_composite: expected still 5 PKs, got :meta_pk_count
+\echo [FAIL] (:testid) prefill_composite: expected still 3 PKs, got :meta_pk_count
 SELECT (:fail::int + 1) AS fail \gset
 \endif