bpo-41069: Make TESTFN and the CWD for tests containing non-ascii characters. (GH-21035)

2 files changed, 12 insertions, 11 deletions

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index 5707d8e..f8f60fb 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -20,7 +20,7 @@ from .import_helper import (
     forget, import_fresh_module, import_module, make_legacy_pyc,
     modules_cleanup, modules_setup, unload)
 from .os_helper import (
-    FS_NONASCII, SAVEDCWD, TESTFN, TESTFN_NONASCII,
+    FS_NONASCII, SAVEDCWD, TESTFN, TESTFN_ASCII, TESTFN_NONASCII,
     TESTFN_UNENCODABLE, TESTFN_UNDECODABLE,
     TESTFN_UNICODE, can_symlink, can_xattr,
     change_cwd, create_empty_file, fd_count,
diff --git a/Lib/test/support/os_helper.py b/Lib/test/support/os_helper.py
index d334702..d9807a1 100644
--- a/Lib/test/support/os_helper.py
+++ b/Lib/test/support/os_helper.py
@@ -13,16 +13,16 @@ import warnings
 # Filename used for testing
 if os.name == 'java':
     # Jython disallows @ in module names
-    TESTFN = '$test'
+    TESTFN_ASCII = '$test'
 else:
-    TESTFN = '@test'
+    TESTFN_ASCII = '@test'
 
 # Disambiguate TESTFN for parallel testing, while letting it remain a valid
 # module name.
-TESTFN = "{}_{}_tmp".format(TESTFN, os.getpid())
+TESTFN_ASCII = "{}_{}_tmp".format(TESTFN_ASCII, os.getpid())
 
 # TESTFN_UNICODE is a non-ascii filename
-TESTFN_UNICODE = TESTFN + "-\xe0\xf2\u0258\u0141\u011f"
+TESTFN_UNICODE = TESTFN_ASCII + "-\xe0\xf2\u0258\u0141\u011f"
 if sys.platform == 'darwin':
     # In Mac OS X's VFS API file names are, by definition, canonically
     # decomposed Unicode, encoded using UTF-8. See QA1173:
@@ -39,7 +39,7 @@ if os.name == 'nt':
     if sys.getwindowsversion().platform >= 2:
         # Different kinds of characters from various languages to minimize the
         # probability that the whole name is encodable to MBCS (issue #9819)
-        TESTFN_UNENCODABLE = TESTFN + "-\u5171\u0141\u2661\u0363\uDC80"
+        TESTFN_UNENCODABLE = TESTFN_ASCII + "-\u5171\u0141\u2661\u0363\uDC80"
         try:
             TESTFN_UNENCODABLE.encode(sys.getfilesystemencoding())
         except UnicodeEncodeError:
@@ -56,7 +56,7 @@ elif sys.platform != 'darwin':
         b'\xff'.decode(sys.getfilesystemencoding())
     except UnicodeDecodeError:
         # 0xff will be encoded using the surrogate character u+DCFF
-        TESTFN_UNENCODABLE = TESTFN \
+        TESTFN_UNENCODABLE = TESTFN_ASCII \
             + b'-\xff'.decode(sys.getfilesystemencoding(), 'surrogateescape')
     else:
         # File system encoding (eg. ISO-8859-* encodings) can encode
@@ -64,8 +64,8 @@ elif sys.platform != 'darwin':
         pass
 
 # FS_NONASCII: non-ASCII character encodable by os.fsencode(),
-# or None if there is no such character.
-FS_NONASCII = None
+# or an empty string if there is no such character.
+FS_NONASCII = ''
 for character in (
     # First try printable and common characters to have a readable filename.
     # For each character, the encoding list are just example of encodings able
@@ -141,13 +141,14 @@ for name in (
     try:
         name.decode(sys.getfilesystemencoding())
     except UnicodeDecodeError:
-        TESTFN_UNDECODABLE = os.fsencode(TESTFN) + name
+        TESTFN_UNDECODABLE = os.fsencode(TESTFN_ASCII) + name
         break
 
 if FS_NONASCII:
-    TESTFN_NONASCII = TESTFN + '-' + FS_NONASCII
+    TESTFN_NONASCII = TESTFN_ASCII + FS_NONASCII
 else:
     TESTFN_NONASCII = None
+TESTFN = TESTFN_NONASCII or TESTFN_ASCII
 
 
 def make_bad_fd():