Crash on unable-to-decrypt errors on webkit branch

[ara4n]

2019-04-07 18:15:18.130798+0200 Seaglass[3338:8100804] [MXCrypto] decryptEvent: Unable to decrypt (null)
2019-04-07 18:15:18.130846+0200 Seaglass[3338:8100804] [MXTimeline] addEvent: Warning: Unable to decrypt event: (null)
Error: Error Domain=org.matrix.sdk.decryption Code=2 "Unable to decrypt" UserInfo={NSLocalizedDescription=Unable to decrypt, NSLocalizedFailureReason=Unable to decrypt $146549358040426FbVJa:matrix.org: m.room.encrypted - 2016-06-09 17:33:00 +0000: {
}. Algoritm: (null)}
2019-04-07 18:15:18.181915+0200 Seaglass[3338:8100804] [MXEventTimeline] paginate: is done
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = Fatal error: Unexpectedly found nil while unwrapping an Optional value
    frame #0: 0x0000000101be7b20 libswiftCore.dylib`_swift_runtime_on_report
    frame #1: 0x0000000101c39401 libswiftCore.dylib`_swift_stdlib_reportFatalError + 113
    frame #2: 0x000000010194114a libswiftCore.dylib`function signature specialization <Arg[1] = [Closure Propagated : reabstraction thunk helper from @callee_guaranteed (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> () to @escaping @callee_guaranteed (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> (@out ()), Argument Types : [@callee_guaranteed (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> ()]> of generic specialization <()> of Swift.StaticString.withUTF8Buffer<A>((Swift.UnsafeBufferPointer<Swift.UInt8>) -> A) -> A + 58
    frame #3: 0x0000000101bc78fe libswiftCore.dylib`partial apply forwarder for closure #2 (Swift.UnsafeBufferPointer<Swift.UInt8>) -> () in Swift._fatalErrorMessage(_: Swift.StaticString, _: Swift.StaticString, file: Swift.StaticString, line: Swift.UInt, flags: Swift.UInt32) -> Swift.Never + 110
    frame #4: 0x000000010194114a libswiftCore.dylib`function signature specialization <Arg[1] = [Closure Propagated : reabstraction thunk helper from @callee_guaranteed (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> () to @escaping @callee_guaranteed (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> (@out ()), Argument Types : [@callee_guaranteed (@unowned Swift.UnsafeBufferPointer<Swift.UInt8>) -> ()]> of generic specialization <()> of Swift.StaticString.withUTF8Buffer<A>((Swift.UnsafeBufferPointer<Swift.UInt8>) -> A) -> A + 58
    frame #5: 0x0000000101b09939 libswiftCore.dylib`function signature specialization <Arg[2] = Dead, Arg[3] = Dead> of Swift._fatalErrorMessage(_: Swift.StaticString, _: Swift.StaticString, file: Swift.StaticString, line: Swift.UInt, flags: Swift.UInt32) -> Swift.Never + 105
    frame #6: 0x0000000101940c23 libswiftCore.dylib`Swift._fatalErrorMessage(_: Swift.StaticString, _: Swift.StaticString, file: Swift.StaticString, line: Swift.UInt, flags: Swift.UInt32) -> Swift.Never + 19
  * frame #7: 0x0000000100021543 Seaglass`MainViewRoomController.webView(webView=0x0000600003b6aae0, navigation=0x0000000113474e50, self=0x0000600003d5cb40) at MainViewRoomController.swift:81
    frame #8: 0x0000000100022a11 Seaglass`@objc MainViewRoomController.webView(_:didFinish:) at <compiler-generated>:0
    frame #9: 0x00007fff57e7ba39 WebKit`WebKit::NavigationState::NavigationClient::didFinishNavigation(WebKit::WebPageProxy&, API::Navigation*, API::Object*) + 93
    frame #10: 0x00007fff5807ea0b WebKit`WebKit::WebPageProxy::didFinishLoadForFrame(unsigned long long, unsigned long long, WebKit::UserData const&) + 339
    frame #11: 0x00007fff5809a0b0 WebKit`WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 9596
    frame #12: 0x00007fff57e7708f WebKit`IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 127
    frame #13: 0x00007fff580fe000 WebKit`WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 24
    frame #14: 0x00007fff57e43e48 WebKit`IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 130
    frame #15: 0x00007fff57e466e7 WebKit`IPC::Connection::dispatchIncomingMessages() + 731
    frame #16: 0x00007fff4c86d047 JavaScriptCore`WTF::RunLoop::performWork() + 231
    frame #17: 0x00007fff4c86d2d2 JavaScriptCore`WTF::RunLoop::performWork(void*) + 34
    frame #18: 0x00007fff49268395 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
    frame #19: 0x00007fff4926833b CoreFoundation`__CFRunLoopDoSource0 + 108
    frame #20: 0x00007fff4924bdd1 CoreFoundation`__CFRunLoopDoSources0 + 195
    frame #21: 0x00007fff4924b37a CoreFoundation`__CFRunLoopRun + 1219
    frame #22: 0x00007fff4924ac64 CoreFoundation`CFRunLoopRunSpecific + 463
    frame #23: 0x00007fff484e1ab5 HIToolbox`RunCurrentEventLoopInMode + 293
    frame #24: 0x00007fff484e17eb HIToolbox`ReceiveNextEventCommon + 618
    frame #25: 0x00007fff484e1568 HIToolbox`_BlockUntilNextEventMatchingListInModeWithFilter + 64
    frame #26: 0x00007fff4679c363 AppKit`_DPSNextEvent + 997
    frame #27: 0x00007fff4679b102 AppKit`-[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1362
    frame #28: 0x00007fff46795165 AppKit`-[NSApplication run] + 699
    frame #29: 0x00007fff467848a3 AppKit`NSApplicationMain + 780
    frame #30: 0x0000000100040eed Seaglass`main at AppDelegate.swift:22
    frame #31: 0x00007fff7649ced9 libdyld.dylib`start + 1