[PULL 17/25] tests/qapi-schema: Rewrite simple union TestIfUnion to be flat

[Markus Armbruster <armbru@redhat.com>]

Simple unions predate flat unions.  Having both complicates the QAPI
schema language and the QAPI generator.  We haven't been using simple
unions in new code for a long time, because they are less flexible and
somewhat awkward on the wire.

To prepare for their removal, rewrite TestIfUnion to be flat.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210917143134.412106-18-armbru@redhat.com>
---
 tests/qapi-schema/qapi-schema-test.json |  4 +++-
 tests/qapi-schema/qapi-schema-test.out  | 16 ++++++----------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index eae43f41c4..ef17ab1aae 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -229,8 +229,10 @@
   'if': 'TEST_IF_ENUM' }
 
 { 'union': 'TestIfUnion',
+  'base': { 'type': 'TestIfEnum' },
+  'discriminator': 'type',
   'data': { 'foo': 'TestStruct',
-            'bar': { 'type': 'str', 'if': 'TEST_IF_UNION_BAR'} },
+            'bar': { 'type': 'UserDefZero', 'if': 'TEST_IF_ENUM_BAR'} },
   'if': { 'all': ['TEST_IF_UNION', 'TEST_IF_STRUCT'] } }
 
 { 'command': 'test-if-union-cmd',
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index e43073d795..07e4161331 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -257,19 +257,15 @@ enum TestIfEnum
     member bar
         if TEST_IF_ENUM_BAR
     if TEST_IF_ENUM
-object q_obj_TestStruct-wrapper
-    member data: TestStruct optional=False
-enum TestIfUnionKind
-    member foo
-    member bar
-        if TEST_IF_UNION_BAR
+object q_obj_TestIfUnion-base
+    member type: TestIfEnum optional=False
     if {'all': ['TEST_IF_UNION', 'TEST_IF_STRUCT']}
 object TestIfUnion
-    member type: TestIfUnionKind optional=False
+    base q_obj_TestIfUnion-base
     tag type
-    case foo: q_obj_TestStruct-wrapper
-    case bar: q_obj_str-wrapper
-        if TEST_IF_UNION_BAR
+    case foo: TestStruct
+    case bar: UserDefZero
+        if TEST_IF_ENUM_BAR
     if {'all': ['TEST_IF_UNION', 'TEST_IF_STRUCT']}
 object q_obj_test-if-union-cmd-arg
     member union-cmd-arg: TestIfUnion optional=False
-- 
2.31.1