lib-http: client: Prevent useless and unexpected request callbacks du…

…ring http_client_deinit().

Requests are now destroyed before queues, hosts, peers and connections.
As a side-effect, requests are now removed from the client request list at http_client_request_destroy(), so that requests with lingering references will no longer make http_client_wait() hang.

src/lib-http/http-client-private.h

@@ -131,6 +131,7 @@ struct http_client_request {
 	unsigned int payload_wait:1;
 	unsigned int urgent:1;
 	unsigned int submitted:1;
+	unsigned int listed:1;
 	unsigned int connect_tunnel:1;
 	unsigned int connect_direct:1;
 	unsigned int ssl_tunnel:1;

src/lib-http/http-client-request.c

@@ -151,6 +151,32 @@ http_client_request_connect_ip(struct http_client *client,
 	return req;
 }
 
+static void
+http_client_request_add(struct http_client_request *req)
+{
+	struct http_client *client = req->client;
+
+	DLLIST_PREPEND(&client->requests_list, req);
+	client->requests_count++;
+	req->listed = TRUE;
+}
+
+static void
+http_client_request_remove(struct http_client_request *req)
+{
+	struct http_client *client = req->client;
+
+	if (req->listed) {
+		/* only decrease pending request counter if this request was submitted */
+		DLLIST_REMOVE(&client->requests_list, req);
+		client->requests_count--;
+	}
+	req->listed = FALSE;
+
+	if (client->requests_count == 0 && client->ioloop != NULL)
+		io_loop_stop(client->ioloop);
+}
+
 void http_client_request_ref(struct http_client_request *req)
 {
 	i_assert(req->refcount > 0);
@@ -183,11 +209,7 @@ bool http_client_request_unref(struct http_client_request **_req)
 		req->destroy_callback = NULL;
 	}
 
-	/* only decrease pending request counter if this request was submitted */
-	if (req->submitted) {
-		DLLIST_REMOVE(&client->requests_list, req);
-		client->requests_count--;
-	}
+	http_client_request_remove(req);
 
 	if (client->requests_count == 0 && client->ioloop != NULL)
 		io_loop_stop(client->ioloop);
@@ -214,6 +236,10 @@ void http_client_request_destroy(struct http_client_request **_req)
 	http_client_request_debug(req, "Destroy (requests left=%d)",
 		client->requests_count);
 
+	if (req->state < HTTP_REQUEST_STATE_FINISHED)
+		req->state = HTTP_REQUEST_STATE_ABORTED;
+	req->callback = NULL;
+
 	if (req->queue != NULL)
 		http_client_queue_drop_request(req->queue, req);
 
@@ -223,6 +249,7 @@ void http_client_request_destroy(struct http_client_request **_req)
 		req->destroy_callback = NULL;
 		callback(req->destroy_context);
 	}
+	http_client_request_remove(req);
 	http_client_request_unref(&req);
 }
 
@@ -589,16 +616,13 @@ static void http_client_request_do_submit(struct http_client_request *req)
 
 void http_client_request_submit(struct http_client_request *req)
 {
-	struct http_client *client = req->client;
-
 	req->submit_time = ioloop_timeval;
 
 	http_client_request_do_submit(req);
 	http_client_request_debug(req, "Submitted");
 
 	req->submitted = TRUE;
-	DLLIST_PREPEND(&client->requests_list, req);
-	client->requests_count++;
+	http_client_request_add(req);
 }
 
 void

src/lib-http/http-client.c

@@ -163,24 +163,20 @@ struct http_client *http_client_init(const struct http_client_settings *set)
 void http_client_deinit(struct http_client **_client)
 {
 	struct http_client *client = *_client;
-	struct http_client_request *req, *const *req_idx;
+	struct http_client_request *req;
 	struct http_client_host *host;
 	struct http_client_peer *peer;
 
 	*_client = NULL;
 
-	/* drop delayed failing requests */
-	while (array_count(&client->delayed_failing_requests) > 0) {
-		req_idx = array_idx(&client->delayed_failing_requests, 0);
-		req = *req_idx;
-
-		i_assert(req->refcount == 1);
-		http_client_request_error_delayed(&req);
+	/* destroy requests without calling callbacks */
+	req = client->requests_list;
+	while (req != NULL) {
+		struct http_client_request *next_req = req->next;
+		http_client_request_destroy(&req);
+		req = next_req;
 	}
-	array_free(&client->delayed_failing_requests);
-
-	if (client->to_failing_requests != NULL)
-		timeout_remove(&client->to_failing_requests);
+	i_assert(client->requests_count == 0);
 
 	/* free peers */
 	while (client->peers_list != NULL) {
@@ -196,6 +192,10 @@ void http_client_deinit(struct http_client **_client)
 	}
 	hash_table_destroy(&client->hosts);
 
+	array_free(&client->delayed_failing_requests);
+	if (client->to_failing_requests != NULL)
+		timeout_remove(&client->to_failing_requests);
+
 	connection_list_deinit(&client->conn_list);
 
 	if (client->ssl_ctx != NULL)