[tor-commits] [tor/master] Add some clarity and checks to cell_queue_append_packed_copy

[nickm at torproject.org]

commit f6fee77375d246d3607b82577464a499685c1ce6
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Oct 30 23:00:52 2013 -0400

    Add some clarity and checks to cell_queue_append_packed_copy
    
    It's not cool to have "circ may be NULL if use_stats false, but
    otherwise we crash" as an undocumented API constraint. :)
---
 src/or/relay.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/or/relay.c b/src/or/relay.c
index 7947ca3..e0b5d26 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -2204,7 +2204,9 @@ cell_command_queue_pop(uint8_t *command, cell_queue_t *queue)
 }
 
 /** Append a newly allocated copy of <b>cell</b> to the end of the
- * <b>exitward</b> (or app-ward) <b>queue</b> of <b>circ</b>. */
+ * <b>exitward</b> (or app-ward) <b>queue</b> of <b>circ</b>.  If
+ * <b>use_stats</b> is true, record statistics about the cell.
+ */
 void
 cell_queue_append_packed_copy(circuit_t *circ, cell_queue_t *queue,
                               int exitward, const cell_t *cell,
@@ -2244,7 +2246,7 @@ cell_queue_append_packed_copy(circuit_t *circ, cell_queue_t *queue,
   }
   /* Remember that we added a cell to the queue, and remember the cell
    * command. */
-  if (get_options()->TestingEnableCellStatsEvent) {
+  if (get_options()->TestingEnableCellStatsEvent && circ) {
     testing_cell_stats_entry_t *ent =
                       tor_malloc_zero(sizeof(testing_cell_stats_entry_t));
     ent->command = cell->command;