qapi-schema: test: add a qapi-schema-test for array alternates

Check that conflicts among array alternates are detected correctly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220321164243.200569-3-pbonzini@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Expected test output alternate-conflict-lists.json corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

tests/qapi-schema/alternate-conflict-lists.err

@@ -0,0 +1,2 @@
+alternate-conflict-lists.json: In alternate 'Alt':
+alternate-conflict-lists.json:4: branch 'two' can't be distinguished from 'one'

tests/qapi-schema/alternate-conflict-lists.json

@@ -0,0 +1,6 @@
+# Two lists conflict even if their inner types would be compatible
+{ 'struct': 'One',
+  'data': { 'name': 'str' } }
+{ 'alternate': 'Alt',
+  'data': { 'one': [ 'int' ],
+            'two': [ 'str' ] } }

tests/qapi-schema/meson.build

@@ -11,6 +11,7 @@ schemas = [
   'alternate-conflict-dict.json',
   'alternate-conflict-enum-bool.json',
   'alternate-conflict-enum-int.json',
+  'alternate-conflict-lists.json',
   'alternate-conflict-string.json',
   'alternate-conflict-bool-string.json',
   'alternate-conflict-num-string.json',