closes#9274
ref #9028
If stdin closed then read_error_exit calls preserve_exit. Handling
SIGHUP during preserve_exit would cause a premature teardown, and
conflicts with e.g. ui_bridge_stop which waits for TUI to teardown.
Vim ignores SIGHUP in its prepare_to_exit and getout_preserve_modified
routines:
/* Ignore SIGHUP, because a dropped connection causes a read error, which
* makes Vim exit and then handling SIGHUP causes various reentrance
* problems. */
signal(SIGHUP, SIG_IGN);
1. Don't check elapsed time in children_kill_cb(), it's already implied
by the start-time of the timer itself.
2. Restart timer from children_kill_cb() for PTY jobs, to send SIGKILL
after SIGTERM. There is an edge case where SIGKILL might follow
SIGTERM too quickly, if jobstop() is called near the 2-second timer
window. But this edge case is not worth code complication.
Let the terminal dictate the normal-mode cursor position. This will be
disorienting sometimes, but it is closer to what users expect vs always
going to the last line.
It is otherwise impossible to determine which test failed sanitizer/valgrind
check. test/functional/helpers.lua module return was changed so that tests which
do not provide after_each function to get new check will automatically fail.
