Fix fd.o #10174: make it possible to return multiple values with no signature.

More specifically: when a service method with no signature synchronously
returns a tuple that is not a Struct, interpret it as a multi-valued return,
rather than as a structure.

This is a common Python idiom, and returning a struct makes little sense
anyway when D-Bus lets you return multiple values.

Returned lists are still interpreted as arrays - returning an array is
entirely sensible, and indeed likely to be common.

Async service methods are unaffected (there is no ambiguity), and it's still
possible to return a structure by returning a dbus.Struct with appropriate
contents.

https://bugs.freedesktop.org/show_bug.cgi?id=10174

2 files changed, 11 insertions, 0 deletions

diff --git a/test/test-client.py b/test/test-client.py
index 49578f7..de180ef 100755
--- a/test/test-client.py
+++ b/test/test-client.py
@@ -336,6 +336,12 @@ class TestDBusBindings(unittest.TestCase):
         ret = bus.name_has_owner('org.freedesktop.DBus.Python.TestName')
         self.assert_(not ret, 'deleting reference failed to release BusName org.freedesktop.DBus.Python.TestName')
 
+    def testMultipleReturnWithoutSignature(self):
+        # https://bugs.freedesktop.org/show_bug.cgi?id=10174
+        ret = self.iface.MultipleReturnWithoutSignature()
+        self.assert_(not isinstance(ret, dbus.Struct), repr(ret))
+        self.assertEquals(ret, ('abc', 123))
+
 """ Remove this for now
 class TestDBusPythonToGLibBindings(unittest.TestCase):
     def setUp(self):
diff --git a/test/test-service.py b/test/test-service.py
index 601ee5e..5c6fcdb 100755
--- a/test/test-service.py
+++ b/test/test-service.py
@@ -183,6 +183,11 @@ class TestObject(dbus.service.Object, TestInterface):
     def WhoAmI(self, sender):
         return sender
 
+    @dbus.service.method(IFACE)
+    def MultipleReturnWithoutSignature(self):
+        # https://bugs.freedesktop.org/show_bug.cgi?id=10174
+        return dbus.String('abc'), dbus.Int32(123)
+
 session_bus = dbus.SessionBus()
 name = dbus.service.BusName("org.freedesktop.DBus.TestSuitePythonService", bus=session_bus)
 object = TestObject(name)