[PATCH v3 03/11] gdb, remote: fix async handler assertion on reconnect to non-stop target

[Mohamed Bouhaouel <mohamed.bouhaouel@intel.com>]

From: "Bouhaouel, Mohamed" <mohamed.bouhaouel@intel.com>

When reconnecting to a non-stop remote target during
process_initial_stop_replies (), the code attempts to mark an async event
handler before async mode is enabled.  This causes an assertion failure
in remote_state::mark_async_event_handler (), which requires the serial
connection to be in async mode (is_async_p () == true).

Fix by changing the condition in queued_stop_reply () from
target_can_async_p () to target_is_async_p (), matching the pattern used
in push_stop_reply ().  When async mode is later enabled, the event
handler will be marked then.

Scenario:
    - Connect to non-stop remote target.
    - Thread receives signal (e.g., SIGUSR1) and stops.
    - Disconnect and reconnect.
    - Assertion fails because mark_async_event_handler () requires
      is_async_p ().

Reproducible when running gdb.threads/reconnect-signal.exp, on
native-gdbserver or native-extended-gdbserver with target-non-stop
enabled.

export GDBFLAGS="-iex \"maint set target-non-stop on\""
make check TESTS="gdb.threads/reconnect-signal.exp" \
    RUNTESTFLAGS="--target_board=native-gdbserver GDBFLAGS='$GDBFLAGS'"
---
 gdb/remote.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/remote.c b/gdb/remote.c
index caf0579e94e..646af2ffca6 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8325,7 +8325,7 @@ remote_target::queued_stop_reply (ptid_t ptid)
   remote_state *rs = get_remote_state ();
   stop_reply_up r = remote_notif_remove_queued_reply (ptid);
 
-  if (!rs->stop_reply_queue.empty () && target_can_async_p ())
+  if (!rs->stop_reply_queue.empty () && target_is_async_p ())
     {
       /* There's still at least an event left.  */
       rs->mark_async_event_handler ();
-- 
2.43.0

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