add domain to reactlog for context exit

[schloerke]

Fixes #2177

The domain being saved when the context was exiting is not properly saved when a top level context is exiting.

The errors received in #2177 were due to a NULL session token. When only looking at a single session, this was not an issue. When looking at the result of multiple sessions, either session would improperly capture the extra exits being generated in the global session space (when they are really session specific).

Regular, single session exit tokens done in a session only. The default global domain token is not being captured properly, while the local .domain$token value is captured correctly.

$id
[1] "4"

$token
[1] "8af79d835e15cbc31cb8d28f2fe79cea"

$defaultToken
[1] "8af79d835e15cbc31cb8d28f2fe79cea"

$id
[1] "3"

$token
[1] "8af79d835e15cbc31cb8d28f2fe79cea"

$defaultToken
[1] "8af79d835e15cbc31cb8d28f2fe79cea"

$id
[1] "2"

$token
[1] "8af79d835e15cbc31cb8d28f2fe79cea"

$defaultToken
NULL

$id
[1] "5"

$token
[1] "8af79d835e15cbc31cb8d28f2fe79cea"

$defaultToken
NULL

[schloerke]

Code to see missing exit domain tokens..

shiny:::.graphStack$as_list() %>% 
  Filter(f = function(x) {x$action %in% c("enter", "exit")}) %>% 
  lapply(function(x) { x$session <- x$session %||% "NULL"; x}) %>% 
  dplyr::bind_rows() %>% 
  as.data.frame() 
-> a

print(dplyr::filter(a, action == "enter")); print(dplyr::filter(a, action == "exit"))

  action id                          session       time
1  enter  2 5753a1c582196b6d6223ba700f9f2bd4 1536603581
2  enter  3 5753a1c582196b6d6223ba700f9f2bd4 1536603581
3  enter  4 5753a1c582196b6d6223ba700f9f2bd4 1536603581
4  enter  5 5753a1c582196b6d6223ba700f9f2bd4 1536603581
5  enter  7 b77cba493f47b2362ddcaa2ceb700801 1536603598
6  enter  8 b77cba493f47b2362ddcaa2ceb700801 1536603598
7  enter  9 b77cba493f47b2362ddcaa2ceb700801 1536603598
8  enter 10 b77cba493f47b2362ddcaa2ceb700801 1536603598
  action id                          session       time
1   exit  4 5753a1c582196b6d6223ba700f9f2bd4 1536603581
2   exit  3 5753a1c582196b6d6223ba700f9f2bd4 1536603581
3   exit  2                             NULL 1536603581
4   exit  5                             NULL 1536603581
5   exit  9 b77cba493f47b2362ddcaa2ceb700801 1536603598
6   exit  8 b77cba493f47b2362ddcaa2ceb700801 1536603598
7   exit  7                             NULL 1536603598
8   exit 10                             NULL 1536603598