[3.11] [3.12] gh-117347: Fix test_clinic side effects (GH-117363) (GH-117365) (#117366)

[3.12] gh-117347: Fix test_clinic side effects (GH-117363) (GH-117365)

gh-117347: Fix test_clinic side effects (GH-117363)

Save/restore converters in ClinicWholeFileTest and
ClinicExternalTest.

(cherry picked from commit c80d138)

Co-authored-by: Victor Stinner <vstinner@python.org>
(cherry picked from commit 35b6c4a)

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

Author: miss-islington

Lib/test/test_clinic.py

@@ -22,6 +22,20 @@
     from clinic import DSLParser
 
 
+def restore_dict(converters, old_converters):
+    converters.clear()
+    converters.update(old_converters)
+
+
+def save_restore_converters(testcase):
+    testcase.addCleanup(restore_dict, clinic.converters,
+                        clinic.converters.copy())
+    testcase.addCleanup(restore_dict, clinic.legacy_converters,
+                        clinic.legacy_converters.copy())
+    testcase.addCleanup(restore_dict, clinic.return_converters,
+                        clinic.return_converters.copy())
+
+
 class _ParserBase(TestCase):
     maxDiff = None
 
@@ -108,6 +122,7 @@ def directive(self, name, args):
 
 class ClinicWholeFileTest(_ParserBase):
     def setUp(self):
+        save_restore_converters(self)
         self.clinic = clinic.Clinic(clinic.CLanguage(None), filename="test.c")
 
     def expect_failure(self, raw):
@@ -1317,6 +1332,9 @@ class ClinicExternalTest(TestCase):
     maxDiff = None
     clinic_py = os.path.join(test_tools.toolsdir, "clinic", "clinic.py")
 
+    def setUp(self):
+        save_restore_converters(self)
+
     def _do_test(self, *args, expect_success=True):
         with subprocess.Popen(
             [sys.executable, "-Xutf8", self.clinic_py, *args],