fix a import strange loop that affects pypy test appsupport on python2.5

_pytest/assertion/oldinterpret.py

@@ -1,8 +1,7 @@
 import py
 import sys, inspect
 from compiler import parse, ast, pycodegen
-from _pytest.assertion.util import format_explanation
+from _pytest.assertion.util import format_explanation, BuiltinAssertionError
-from _pytest.assertion.reinterpret import BuiltinAssertionError
 
 passthroughex = py.builtin._sysex
 

_pytest/assertion/reinterpret.py

@@ -1,7 +1,6 @@
 import sys
 import py
-
+from _pytest.assertion.util import BuiltinAssertionError
-BuiltinAssertionError = py.builtin.builtins.AssertionError
 
 class AssertionError(BuiltinAssertionError):
     def __init__(self, *args):

_pytest/assertion/util.py

@@ -2,6 +2,7 @@
 
 import py
 
+BuiltinAssertionError = py.builtin.builtins.AssertionError
 
 # The _reprcompare attribute on the util module is used by the new assertion
 # interpretation code and assertion rewriter to detect this plugin was

testing/test_assertinterpret.py

@@ -322,3 +322,18 @@ def test_assert_raises_in_nonzero_of_object_pytest_issue10():
         e = exvalue()
         s = str(e)
         assert "<MY42 object> < 0" in s
+
+@py.test.mark.skipif("sys.version_info >= (2,6)")
+def test_oldinterpret_importation():
+    # we had a cyclic import there
+    # requires pytest on sys.path
+    res = py.std.subprocess.call([
+        py.std.sys.executable, '-c', str(py.code.Source("""
+        try:
+            from _pytest.assertion.newinterpret import interpret
+        except ImportError:
+            from _pytest.assertion.oldinterpret import interpret
+        """))
+    ])
+
+    assert res == 0