Test final-page update races and replication read failures

tests/test_media_replication.c

@@ -228,6 +228,20 @@ static void test_atomic_and_validation(void) {
     bad = response;
     struct media_pkt_sync_entry* rows = (struct media_pkt_sync_entry*)(bad.data + MEDIA_SYNC_RESP_HDR_SIZE);
     rows[1].status = 3; receive(a, &bad);
+    for (int fault = 0; fault < 8; fault++) {
+        bad = response;
+        struct media_pkt_sync_resp* h = (struct media_pkt_sync_resp*)bad.data;
+        rows = (struct media_pkt_sync_entry*)(bad.data + sizeof(*h));
+        if (fault == 0) bad.len++;
+        if (fault == 1) write_le(&h->num_entries, 33, 2);
+        if (fault == 2) h->status = 3;
+        if (fault == 3) write_le(&h->next_id, UINT64_MAX, 8);
+        if (fault == 4) rows[1].id = rows[0].id;
+        if (fault == 5) memset(&rows[0].node_id, 0, 8);
+        if (fault == 6) write_le(&rows[1].timestamp, UINT64_MAX, 8);
+        if (fault == 7) memcpy(rows[1].block_id, rows[0].block_id, 16);
+        receive(a, &bad);
+    }
     REQUIRE(sp->request_pending && sp->deadline_tb == deadline && !scalar(a->md.db, "SELECT COUNT(*) FROM super_sync"));
     REQUIRE(!scalar(a->md.db, "SELECT COUNT(*) FROM block_availability"));
     const char* failures[] = {
@@ -304,6 +318,38 @@ static struct packet respond_to(struct UTUN_INSTANCE* source, const struct packe
 
 static int reject_commit(void* arg) { (void)arg; return 1; }
 
+static int deny_rows(void* arg, int action, const char* table, const char* column, const char* db, const char* trigger) {
+    (void)arg; (void)column; (void)db; (void)trigger;
+    return action == SQLITE_READ && table && !strcmp(table, "block_availability") ? SQLITE_DENY : SQLITE_OK;
+}
+
+/* Обновление после последнего snapshot: обе перестановки CHANGED/RESP и потеря уведомления. */
+static void test_hints_and_read_error(void) {
+    for (int order = 0; order < 3; order++) {
+        struct UTUN_INSTANCE* a = node(SERVER), *b = node(CLIENT);
+        begin_pull(a, CLIENT, GROUP);
+        struct packet q = request_from(a, CLIENT);
+        struct media_super_peer* sp = peer(a, CLIENT, GROUP);
+        uint64_t deadline = sp->deadline_tb;
+        REQUIRE(sqlite3_set_authorizer(b->md.db, deny_rows, NULL) == SQLITE_OK);
+        struct packet error = respond_to(b, &q);
+        REQUIRE(((struct media_pkt_sync_resp*)error.data)->status == MEDIA_SYNC_DB_ERROR && error.len == MEDIA_SYNC_RESP_HDR_SIZE);
+        receive(a, &error); REQUIRE(sp->request_pending && sp->deadline_tb == deadline);
+        REQUIRE(sqlite3_set_authorizer(b->md.db, NULL, NULL) == SQLITE_OK);
+        struct packet empty = respond_to(b, &q);
+        struct media_index_result r = result(1); seed(b, &r, 1, 1, 0);
+        struct packet hint = {.from = CLIENT, .to = SERVER, .group = GROUP, .len = 1, .data = {MEDIA_SUBCMD_CHANGED}};
+        if (order == 0) receive(a, &hint);
+        receive(a, &empty);
+        if (order == 1) receive(a, &hint);
+        if (order != 0) { packet_count = 0; expire(sp); } /* order=2: потерянный hint, истечение idle-сверки. */
+        q = request_from(a, CLIENT);
+        struct packet filled = respond_to(b, &q); receive(a, &filled);
+        REQUIRE(scalar(a->md.db, "SELECT COUNT(*) FROM block_availability") == 1 && !sp->request_pending);
+        free_node(a); free_node(b); media_index_result_free(&r); reset(); capture_blocks = 1;
+    }
+}
+
 /* Потери запроса/ответа, backoff с тем же UUID, ошибка commit и пересоздание БД источника. */
 static void test_retry_and_epoch(void) {
     struct UTUN_INSTANCE* a = node(SERVER), *b = node(CLIENT);
@@ -405,6 +451,7 @@ int main(void) {
     test_atomic_and_validation();
     test_convergence_and_lifecycle();
     test_retry_and_epoch();
+    test_hints_and_read_error();
     test_backpressure();
     REQUIRE(cm_opened == cm_closed);
     uasync_destroy(ua, 0);