Fix a bug in DAP scopes code

While working on static links, I noticed that the DAP scopes code does
not handle the scenario where a frame decorator returns None.  This
situation should be handled identically to a frame decorator returning
an empty iterator.

(cherry picked from commit e9dacb1d6caa5770d3e1722adc0ec74ff13a7a89)

1 files changed, 6 insertions, 2 deletions

diff --git a/gdb/python/lib/gdb/dap/scopes.py b/gdb/python/lib/gdb/dap/scopes.py
index 87f2ed7..13c3581 100644
--- a/gdb/python/lib/gdb/dap/scopes.py
+++ b/gdb/python/lib/gdb/dap/scopes.py
@@ -107,10 +107,14 @@ def _get_scope(id):
     else:
         frame = frame_for_id(id)
         scopes = []
-        args = frame.frame_args()
+        # Make sure to handle the None case as well as the empty
+        # iterator case.
+        args = tuple(frame.frame_args() or ())
         if args:
             scopes.append(_ScopeReference("Arguments", "arguments", frame, args))
-        locs = frame.frame_locals()
+        # Make sure to handle the None case as well as the empty
+        # iterator case.
+        locs = tuple(frame.frame_locals() or ())
         if locs:
             scopes.append(_ScopeReference("Locals", "locals", frame, locs))
         scopes.append(_RegisterReference("Registers", frame))