sched: When releasing a channel, do not BUG() if absent from the pending list

The current code flow makes it that we can release a channel in a PENDING
state but not in the pending list. This happens while the channel is being
processed in the scheduler loop.

Fixes #25125

Signed-off-by: David Goulet <dgoulet@torproject.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/test/test_scheduler.c b/src/test/test_scheduler.c
index 1f014c4f6a..724a6b56b2 100644
--- a/src/test/test_scheduler.c
+++ b/src/test/test_scheduler.c
@@ -502,6 +502,18 @@ perform_channel_state_tests(int KISTSchedRunInterval, int sched_type)
   scheduler_touch_channel(ch1);
   tt_assert(scheduler_compare_channels_mock_ctr > old_count);
 
+  /* Release the ch2 and then do it another time to make sure it doesn't blow
+   * up and we are still in a quiescent state. */
+  scheduler_release_channel(ch2);
+  tt_int_op(ch2->scheduler_state, OP_EQ, SCHED_CHAN_IDLE);
+  tt_int_op(smartlist_len(channels_pending), OP_EQ, 1);
+  /* Cheat a bit so make the release more confused but also will tells us if
+   * the release did put the channel in the right state. */
+  ch2->scheduler_state = SCHED_CHAN_PENDING;
+  scheduler_release_channel(ch2);
+  tt_int_op(ch2->scheduler_state, OP_EQ, SCHED_CHAN_IDLE);
+  tt_int_op(smartlist_len(channels_pending), OP_EQ, 1);
+
   /* Close */
   channel_mark_for_close(ch1);
   tt_int_op(ch1->state, OP_EQ, CHANNEL_STATE_CLOSING);