Correctly disambiguate duplicate errors.

2 files changed, 16 insertions, 1 deletions

diff --git a/lib/fixtures/fixture.py b/lib/fixtures/fixture.py
index 04bcb5d..40e7738 100644
--- a/lib/fixtures/fixture.py
+++ b/lib/fixtures/fixture.py
@@ -23,7 +23,10 @@ __all__ = [
 import itertools
 import sys
 
-from testtools.compat import reraise
+from testtools.compat import (
+    advance_iterator,
+    reraise,
+    )
 from testtools.helpers import try_import
 
 class MultipleExceptions(Exception):
diff --git a/lib/fixtures/tests/test_fixture.py b/lib/fixtures/tests/test_fixture.py
index ed4edf0..8443426 100644
--- a/lib/fixtures/tests/test_fixture.py
+++ b/lib/fixtures/tests/test_fixture.py
@@ -163,6 +163,18 @@ class TestFixture(testtools.TestCase):
             child.addDetail('foo', 'content')
         self.assertEqual({}, parent.getDetails())
 
+    def test_duplicate_details_are_disambiguated(self):
+        parent = fixtures.Fixture()
+        with parent:
+            parent.addDetail('foo', 'parent-content')
+            child = fixtures.Fixture()
+            parent.useFixture(child)
+            # Note that we add the detail *after* using the fixture: the parent
+            # has to query just-in-time.
+            child.addDetail('foo', 'child-content')
+            self.assertEqual({'foo': 'parent-content',
+                              'foo-1': 'child-content',}, parent.getDetails())
+
     def test_addDetail(self):
         fixture = fixtures.Fixture()
         with fixture: