From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Fri, 12 Jun 2026 13:10:41 +0000 (+0200)
Subject: [3.15] gh-151284: Fix test_capi on UBSan (GH-151286) (#151323)
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=5caef8590a06487be5cabdfc890fdc0cd3421751;p=thirdparty%2FPython%2Fcpython.git

[3.15] gh-151284: Fix test_capi on UBSan (GH-151286) (#151323)

gh-151284: Fix test_capi on UBSan (GH-151286)

Comment two checks relying on undefined behavior in
test_fromwidechar() of test_capi.

Enable test_capi in GitHub Action "Reusable Sanitizer".
(cherry picked from commit d87d77287392b78d36a06660228f6a5ca88888d7)

Co-authored-by: Victor Stinner <vstinner@python.org>
---

diff --git a/.github/workflows/reusable-san.yml b/.github/workflows/reusable-san.yml
index 6127c7e1c053..2ceb1000e8a5 100644
--- a/.github/workflows/reusable-san.yml
+++ b/.github/workflows/reusable-san.yml
@@ -82,13 +82,10 @@ jobs:
       run: make -j4
     - name: Display build info
       run: make pythoninfo
-    # test_capi is skipped under UBSan because
-    # they raise signals that UBSan with halt_on_error=1 intercepts.
     - name: Tests
       run: >-
         ./python -m test
         ${{ inputs.sanitizer == 'TSan' && '--tsan' || '' }}
-        ${{ inputs.sanitizer == 'UBSan' && '-x test_capi' || '' }}
         -j4 -W
     - name: Parallel tests
       if: >-
diff --git a/Lib/test/test_capi/test_unicode.py b/Lib/test/test_capi/test_unicode.py
index 5dee25756fe2..0dcd8a25ad01 100644
--- a/Lib/test/test_capi/test_unicode.py
+++ b/Lib/test/test_capi/test_unicode.py
@@ -842,9 +842,7 @@ class CAPITest(unittest.TestCase):
         if SIZEOF_WCHAR_T == 2:
             self.assertEqual(fromwidechar('a\U0001f600'.encode(encoding), 2), 'a\ud83d')
 
-        self.assertRaises(MemoryError, fromwidechar, b'', PY_SSIZE_T_MAX)
         self.assertRaises(SystemError, fromwidechar, b'\0'*SIZEOF_WCHAR_T, -2)
-        self.assertRaises(SystemError, fromwidechar, b'\0'*SIZEOF_WCHAR_T, PY_SSIZE_T_MIN)
         self.assertEqual(fromwidechar(NULL, 0), '')
         self.assertRaises(SystemError, fromwidechar, NULL, 1)
         self.assertRaises(SystemError, fromwidechar, NULL, PY_SSIZE_T_MAX)
@@ -852,6 +850,10 @@ class CAPITest(unittest.TestCase):
         self.assertRaises(SystemError, fromwidechar, NULL, -2)
         self.assertRaises(SystemError, fromwidechar, NULL, PY_SSIZE_T_MIN)
 
+        # The following tests are skipped since they rely on undefined behavior
+        #self.assertRaises(MemoryError, fromwidechar, b'', PY_SSIZE_T_MAX)
+        #self.assertRaises(SystemError, fromwidechar, b'\0'*SIZEOF_WCHAR_T, PY_SSIZE_T_MIN)
+
     @support.cpython_only
     @unittest.skipIf(_testlimitedcapi is None, 'need _testlimitedcapi module')
     def test_aswidechar(self):