[PATCH v6 03/19] qapi/introspect.py: use _make_tree for features nodes

[John Snow <jsnow@redhat.com>]

At present, we open-code this in _make_tree itself; but if the structure
of the tree changes, this is brittle. Use an explicit recursive call to
_make_tree when appropriate to help keep the interior node typing
consistent.

A consequence of doing this is that the 'ifcond' key of the features
dict will be omitted when ifcond is false-ish, just like it is omitted
in top-level calls to _make_tree. This also increases consistency in our
handling of this property.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 scripts/qapi/introspect.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 43ab4be1f77..3295a15c98e 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -30,7 +30,9 @@ def _make_tree(obj, ifcond, features, extra=None):
     if ifcond:
         extra['if'] = ifcond
     if features:
-        obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
+        obj['features'] = [
+            _make_tree(f.name, f.ifcond, None) for f in features
+        ]
     if extra:
         return (obj, extra)
     return obj
-- 
2.29.2