Honor the expected file version before downloading

src/member_files/transfer.c

@@ -360,7 +360,7 @@ static void transfer_response(void* arg, const struct mf_message* r) {
 static void transfer_send_open(struct mf_transfer* t, uint8_t command) {
     struct mf_message q = transfer_packet(t, command);
     q.request_id = 0; q.cursor = command == MF_STAT ? 0 : t->request.id;
-    if (command == MF_STREAM_WRITE) memcpy(q.version, t->request.version, 16);
+    if (command == MF_STREAM_WRITE || command == MF_STAT) memcpy(q.version, t->request.version, 16);
     t->pending = member_files_request(t->files->inst, t->request.group, t->request.server, &q, transfer_response, t);
     if (!t->pending) transfer_stop(t, MF_BUSY);
 }

tests/test_member_files_network.c

@@ -92,6 +92,7 @@ static void api_start(struct network_test* t, unsigned index, int node, int uplo
         .server = t->ids[SERVER], .owner = t->ids[upload ? node : AUTHOR], .upload = upload };
     snprintf(q.remote, sizeof(q.remote), "%s", remote);
     snprintf(q.local, sizeof(q.local), "%s", upload ? source : c->local);
+    if (!upload && source) memcpy(q.version, source, 16);
     c->handle = member_files_transfer_start(&q, api_event, c);
     if (!c->handle) fail(t, "parallel API start");
 }
@@ -262,6 +263,13 @@ static void tick(void* arg) {
         if (!t->api[0].finished || !t->api[1].finished || !t->api[7].finished) goto again;
         if (t->api[0].status || t->api[1].status || t->api[7].status || !check_file(t->api[0].local, BYTES) ||
             !check_file(t->api[1].local, BYTES) || !check_file(t->api[7].local, 0)) { fail(t, "parallel/empty download bytes"); return; }
+        t->phase = 22;
+        uint8_t stale[16]; memset(stale, 0xa5, sizeof(stale));
+        api_start(t, 7, READER, 0, "file.bin", (const char*)stale);
+    } else if (t->phase == 22 && t->api[7].finished) {
+        if (t->api[7].status != MF_STALE || !check_file(t->api[7].local, 0)) {
+            fail(t, "stale download changed existing destination"); return;
+        }
         t->phase = 10; t->answered = 0;
         struct mf_message q = { .command = MF_STAT, .owner = t->ids[AUTHOR] }; snprintf(q.path, sizeof(q.path), "cancelled.bin");
         if (!member_files_request(t->nodes[READER], GROUP, t->ids[SERVER], &q, response, t)) { fail(t, "cancelled STAT"); return; }