gdb/
* linux-nat.c (linux_nat_filter_event): Remove `options'
parameter, and dead code that used it. If we're handling a
PTRACE_EVENT_EXEC event, and the thread group leader is no longer
in our lwp list, re-add it.
(check_zombie_leaders): New.
(linux_nat_wait_1): Remove `options' and `pid' locals. Always
wait for children with WNOHANG, and always wait for all children.
Don't check for no resumed children upfront. Simplify wait loop.
Check for zombie thread group leaders after handling all wait
statuses. Return TARGET_WAITKIND_NO_RESUMED if there no
unwaited-for children left.
* infrun.c (fetch_inferior_event): Handle TARGET_WAITKIND_NO_RESUMED.
(handle_inferior_event): Handle TARGET_WAITKIND_NO_RESUMED.
(normal_stop): Handle TARGET_WAITKIND_NO_RESUMED.
* target.h (enum target_waitkind) <TARGET_WAITKIND_NO_RESUMED>: New.
gdb/testsuite/
* gdb.threads/no-unwaited-for-left.c: New.
* gdb.threads/no-unwaited-for-left.exp: New.
* gdb.threads/non-ldr-exc-1.c: New.
* gdb.threads/non-ldr-exc-1.exp: New.
* gdb.threads/non-ldr-exc-2.c: New.
* gdb.threads/non-ldr-exc-2.exp: New.
* gdb.threads/non-ldr-exc-3.c: New.
* gdb.threads/non-ldr-exc-3.exp: New.
* gdb.threads/non-ldr-exc-4.c: New.
* gdb.threads/non-ldr-exc-4.exp: New.
