Merge issue #26355 fix from Python 3.5

1 files changed, 17 insertions, 2 deletions

diff --git a/Lib/test/test_tools/test_unparse.py b/Lib/test/test_tools/test_unparse.py
index 734bbc215a..65dee1b5ae 100644
--- a/Lib/test/test_tools/test_unparse.py
+++ b/Lib/test/test_tools/test_unparse.py
@@ -134,6 +134,11 @@ class ASTTestCase(unittest.TestCase):
 class UnparseTestCase(ASTTestCase):
     # Tests for specific bugs found in earlier versions of unparse
 
+    def test_fstrings(self):
+        # See issue 25180
+        self.check_roundtrip(r"""f'{f"{0}"*3}'""")
+        self.check_roundtrip(r"""f'{f"{y}"*3}'""")
+
     def test_del_statement(self):
         self.check_roundtrip("del x, y, z")
 
@@ -279,8 +284,18 @@ class DirectoryTestCase(ASTTestCase):
         for filename in names:
             if test.support.verbose:
                 print('Testing %s' % filename)
-            source = read_pyfile(filename)
-            self.check_roundtrip(source)
+
+            # Some f-strings are not correctly round-tripped by
+            #  Tools/parser/unparse.py.  See issue 28002 for details.
+            #  We need to skip files that contain such f-strings.
+            if os.path.basename(filename) in ('test_fstring.py', ):
+                if test.support.verbose:
+                    print(f'Skipping {filename}: see issue 28002')
+                continue
+
+            with self.subTest(filename=filename):
+                source = read_pyfile(filename)
+                self.check_roundtrip(source)
 
 
 if __name__ == '__main__':