xC: fix relay handling of missing log files

Intermediate error messages would trash the prepared static buffer.

1 files changed, 9 insertions, 12 deletions

diff --git a/xC.c b/xC.c
index a589836..5a59a8f 100644
--- a/xC.c
+++ b/xC.c
@@ -15543,14 +15543,13 @@ static void
 client_process_buffer_log
 	(struct client *c, uint32_t seq, struct buffer *buffer)
 {
-	struct relay_event_data_response *e = relay_prepare_response (c->ctx, seq);
-	e->data.command = RELAY_COMMAND_BUFFER_LOG;
-
+	// XXX: We log failures to the global buffer,
+	//   so the client just receives nothing if there is no log file.
+	struct str log = str_make ();
 	char *path = buffer_get_log_path (buffer);
 	FILE *fp = open_log_path (c->ctx, buffer, path);
 	if (fp)
 	{
-		struct str log = str_make ();
 		char buf[BUFSIZ];
 		size_t len;
 		while ((len = fread (buf, 1, sizeof buf, fp)))
@@ -15558,17 +15557,15 @@ client_process_buffer_log
 		if (ferror (fp))
 			log_global_error (c->ctx, "Failed to read `#l': #l",
 				path, strerror (errno));
-
-		// On overflow, it will later fail serialization.
-		e->data.buffer_log.log_len = MIN (UINT32_MAX, log.len);
-		e->data.buffer_log.log = (uint8_t *) str_steal (&log);
 		fclose (fp);
 	}
-
-	// XXX: We log failures to the global buffer,
-	//   so the client just receives nothing if there is no log file.
-
 	free (path);
+
+	struct relay_event_data_response *e = relay_prepare_response (c->ctx, seq);
+	e->data.command = RELAY_COMMAND_BUFFER_LOG;
+	// On overflow, it will later fail serialization (frame will be too long).
+	e->data.buffer_log.log_len = MIN (UINT32_MAX, log.len);
+	e->data.buffer_log.log = (uint8_t *) str_steal (&log);
 	relay_send (c);
 }