Support unicode messages for DBusException in Python 2

[commit message amended -smcv]
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=55899
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>

4 files changed, 116 insertions, 2 deletions

diff --git a/dbus/exceptions.py b/dbus/exceptions.py
index 5283369..21efb06 100644
--- a/dbus/exceptions.py
+++ b/dbus/exceptions.py
@@ -27,6 +27,8 @@ __all__ = ('DBusException', 'MissingErrorHandlerException',
            'IntrospectionParserException', 'UnknownMethodException',
            'NameExistsException')
 
+from dbus._compat import is_py3
+
 
 class DBusException(Exception):
 
@@ -49,15 +51,32 @@ class DBusException(Exception):
                             % ', '.join(kwargs.keys()))
         Exception.__init__(self, *args)
 
-    def __str__(self):
+    def __unicode_for_py2(self):
+        """Return a unicode error"""
+        s = Exception.__unicode__(self)
+        if self._dbus_error_name is not None:
+            return '%s: %s' % (self._dbus_error_name, s)
+        else:
+            return s
+
+    def __str_for_py3(self):
+        """Return a str error"""
         s = Exception.__str__(self)
         if self._dbus_error_name is not None:
             return '%s: %s' % (self._dbus_error_name, s)
         else:
             return s
 
+    if is_py3:
+        __str__ = __str_for_py3
+    else:
+        __unicode__ = __unicode_for_py2
+
     def get_dbus_message(self):
-        s = Exception.__str__(self)
+        if is_py3:
+            s = Exception.__str__(self)
+        else:
+            s = Exception.__unicode__(self)
         if isinstance(s, bytes):
             return s.decode('utf-8', 'replace')
         return s
diff --git a/test/run-test.sh b/test/run-test.sh
index 5648179..76bd075 100755
--- a/test/run-test.sh
+++ b/test/run-test.sh
@@ -67,6 +67,12 @@ echo "DBUS_TOP_BUILDDIR=$DBUS_TOP_BUILDDIR"
 echo "PYTHONPATH=$PYTHONPATH"
 echo "PYTHON=$PYTHON"
 
+# the exceptions handling test is version specific
+PYMAJOR=$($PYTHON -c 'import sys;print(sys.version_info[0])')
+PYTEST=test-exception-py$PYMAJOR.py
+echo "running $PYTEST"
+$PYTHON "$DBUS_TOP_SRCDIR"/test/$PYTEST || die "$PYTEST failed"
+
 echo "running test-standalone.py"
 $PYTHON "$DBUS_TOP_SRCDIR"/test/test-standalone.py || die "test-standalone.py failed"
 
diff --git a/test/test-exception-py2.py b/test/test-exception-py2.py
new file mode 100644
index 0000000..3a8026c
--- /dev/null
+++ b/test/test-exception-py2.py
@@ -0,0 +1,58 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import unittest
+
+import dbus
+
+# from test-service.py
+class ServiceError(dbus.DBusException):
+    """Exception representing a normal "environmental" error"""
+    include_traceback = False
+    _dbus_error_name = 'com.example.Networking.ServerError'
+
+
+class DBusExceptionTestCase(unittest.TestCase):
+    """Test the DBusException str/unicode behavior with py2"""
+
+    def test_dbus_exception_normal(self):
+        """Test the normal Exception behavior"""
+        e = dbus.exceptions.DBusException("baaa")
+        msg = e.get_dbus_message()
+        self.assertEqual(msg, u"baaa")
+
+    def test_dbus_exception_unicode(self):
+        """Test that DBusExceptions that take a py2 unicode work"""
+        e = dbus.exceptions.DBusException(u"bäää")
+        msg = e.get_dbus_message()
+        self.assertEqual(msg, u"bäää")
+
+    def test_dbus_exception_convert_str(self):
+        """Test that converting a DBusException to str() works as expected"""
+        e = dbus.exceptions.DBusException(u"bxxx")
+        self.assertEqual(str(e), "bxxx")
+
+    def test_dbus_exception_convert_str_fail(self):
+        """Test that a non-ascii Exception fails to convert to str"""
+        with self.assertRaises(ValueError):
+            e = dbus.exceptions.DBusException(u"bä")
+            print str(e)
+
+    def test_dbus_exception_convert_unicode(self):
+        """Test that converting a DBusEception to unicode works"""
+        e = dbus.exceptions.DBusException(u"bäää")
+        self.assertEqual(e.get_dbus_message(), u"bäää")
+        self.assertEqual(e.__unicode__(), u"bäää")
+        self.assertEqual(unicode(e), u"bäää")
+
+    def test_subclass_exception_unicode(self):
+        """Test that DBusExceptions that take a py2 unicode work"""
+        e = ServiceError(u"bäää")
+        msg = e.get_dbus_message()
+        self.assertEqual(msg, u"bäää")
+        self.assertEqual(
+            unicode(e), u"com.example.Networking.ServerError: bäää")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/test/test-exception-py3.py b/test/test-exception-py3.py
new file mode 100644
index 0000000..eddb45a
--- /dev/null
+++ b/test/test-exception-py3.py
@@ -0,0 +1,31 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import unittest
+
+import dbus
+
+# from test-service.py
+class ServiceError(dbus.DBusException):
+    """Exception representing a normal "environmental" error"""
+    include_traceback = False
+    _dbus_error_name = 'com.example.Networking.ServerError'
+
+
+class DBusExceptionTestCase(unittest.TestCase):
+
+    def test_dbus_exception(self):
+        e = dbus.exceptions.DBusException("bäää")
+        msg = e.get_dbus_message()
+        self.assertEqual(msg, "bäää")
+        self.assertEqual(str(e), "bäää")
+
+    def test_subclass_exception(self):
+        e = ServiceError("bäää")
+        msg = e.get_dbus_message()
+        self.assertEqual(msg, "bäää")
+        self.assertEqual(str(e), "com.example.Networking.ServerError: bäää")
+
+
+if __name__ == "__main__":
+    unittest.main()