Assert that we don't divide by 0 in random_testing.cc.

This is always true due to the condition function, but if we introduce a
bug that makes the condition not be applied, this causes undefined
behaviour.

1 files changed, 3 insertions, 1 deletions

diff --git a/testing/random_testing.cc b/testing/random_testing.cc
index 4e64c1b4..5ea0bc9d 100644
--- a/testing/random_testing.cc
+++ b/testing/random_testing.cc
@@ -299,10 +299,12 @@ int main() {
             return tox_conference_get_chatlist_size(state.tox()) != 0;
           },
           [](Local_State *state, Random *rnd, std::mt19937 *rng) {
+            size_t chat_count = tox_conference_get_chatlist_size(state->tox());
+            assert(chat_count != 0);  // Condition above.
             TOX_ERR_CONFERENCE_INVITE err;
             tox_conference_invite(
                 state->tox(), rnd->friend_selector(*rng),
-                state->next_invite % tox_conference_get_chatlist_size(state->tox()), &err);
+                state->next_invite % chat_count, &err);
             state->next_invite++;
             assert(err == TOX_ERR_CONFERENCE_INVITE_OK);
           },