Change inferior_to_inferior_object to return a gdbpy_ref

Most callers of inferior_to_inferior_object already use a gdbpy_ref,
so this changes inferior_to_inferior_object to return one.  Doing this
revealed that create_thread_object was not correctly handling the case
where inferior_to_inferior_object failed, so this patch fixes this as
well.

gdb/ChangeLog
2019-01-02  Tom Tromey  <tom@tromey.com>

	* python/python-internal.h (inferior_to_inferior_object): Change
	return type.
	* python/py-exitedevent.c (create_exited_event_object): Update.
	* python/py-inferior.c (inferior_to_inferior_object): Return
	gdbpy_ref.
	(python_new_inferior, python_inferior_deleted)
	(thread_to_thread_object, delete_thread_object)
	(build_inferior_list, gdbpy_selected_inferior): Update.
	* python/py-infthread.c (create_thread_object): Update.  Also fail
	if inferior_to_inferior_object fails.

1 files changed, 5 insertions, 1 deletions

diff --git a/gdb/python/py-infthread.c b/gdb/python/py-infthread.c
index e15e281..bf90d08 100644
--- a/gdb/python/py-infthread.c
+++ b/gdb/python/py-infthread.c
@@ -41,12 +41,16 @@ create_thread_object (struct thread_info *tp)
 {
   thread_object *thread_obj;
 
+  gdbpy_ref<inferior_object> inf_obj = inferior_to_inferior_object (tp->inf);
+  if (inf_obj == NULL)
+    return NULL;
+
   thread_obj = PyObject_New (thread_object, &thread_object_type);
   if (!thread_obj)
     return NULL;
 
   thread_obj->thread = tp;
-  thread_obj->inf_obj = (PyObject *) inferior_to_inferior_object (tp->inf);
+  thread_obj->inf_obj = (PyObject *) inf_obj.release ();
 
   return thread_obj;
 }