Attempting to start a WebRTC peer connection (e.g. via https://webrtc.github.io/samples/src/content/peerconnection/audio/) causes the Socket Process to crash with an assert.

/usr/include/c++/11.1.0/bits/stl_vector.h:1045: std::vector::reference std::vector<nr_ice_stun_server_>::operator[](std::vector::size_type) [_Tp = nr_ice_stun_server_, _Alloc = std::allocator<nr_ice_stun_server_>]: Assertion '__n < this->size()' failed.
Redirecting call to abort() to mozalloc_abort

See e.g. bp-6ccca384-8c51-471b-aeb3-465460220210, which points us at nricectx.cpp:812. servers[0] is invalid when servers is empty.

This is only happening because we compile with stdlib assertions enabled (CXXFLAGS contains -Wp,-D_GLIBCXX_ASSERTIONS).

Bug 1253706, specifically 3bbb2706fe05 removed the guards that presumably kept this from exploding before.

Some other lines, nricectx.cpp:265 and nricectx.cpp:921 correctly turn an empty vector into a nullptr instead of trying to subscript it like SetStunServers and SetTurnServers do.

The right fix here is probably to use servers.data() instead of &servers[0]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=4f683d017c945aae58951ba4acaa28c0902322a0
https://treeherder.mozilla.org/#/jobs?repo=try&revision=a435927ed466e0d3cc5a4ac1da66871144c7e55e
https://treeherder.mozilla.org/#/jobs?repo=try&revision=122ec5ac409e12095254a74793946500e40295c7

Try looks good.

https://hg.mozilla.org/mozilla-central/rev/a7d2fd1431db

Set release status flags based on info from the regressing bug 1253706