[PATCH V2 3/4] libxl/gentypes.py: generate empty map for None field in keyed-union

[Wei Liu <wei.liu2@citrix.com>]

Without this the generated JSON is malformed.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/gentypes.py |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/libxl/gentypes.py b/tools/libxl/gentypes.py
index 1a3b91c..bfb95e2 100644
--- a/tools/libxl/gentypes.py
+++ b/tools/libxl/gentypes.py
@@ -220,6 +220,13 @@ def libxl_C_type_gen_json(ty, v, indent = "    ", parent = None):
             s += "case %s:\n" % f.enumname
             if f.type is not None:
                 s += libxl_C_type_gen_json(f.type, fexpr, indent + "    ", nparent)
+            else:
+                s += "    yajl_gen_map_open(hand);\n"
+                s += "    if (s != yajl_gen_status_ok)\n"
+                s += "        goto out;\n"
+                s += "    yajl_gen_map_close(hand);\n"
+                s += "    if (s != yajl_gen_status_ok)\n"
+                s += "        goto out;\n"
             s += "    break;\n"
         s += "}\n"
     elif isinstance(ty, idl.Struct) and (parent is None or ty.json_fn is None):
-- 
1.7.10.4