Enable test_contextlib

Author: slozier

Src/IronPython/Runtime/Exceptions/PythonExceptions.BaseException.cs

@@ -280,9 +280,6 @@ public BaseException? __context__ {
                 get {
                     return _context ?? __cause__;
                 }
-                internal set {
-                    _context = value;
-                }
             }
 
             public bool __suppress_context__ { get; set; }
@@ -365,7 +362,7 @@ protected internal virtual void InitializeFromClr(System.Exception/*!*/ exceptio
 
             internal Exception CreateClrExceptionWithCause(BaseException? cause, BaseException? context, bool suppressContext) {
                 _cause = cause;
-                _context = context;
+                if (context != this) _context = context;
                 __suppress_context__ = suppressContext;
                 _traceback = null;
 

Src/IronPythonTest/Cases/CPythonCasesManifest.ini

@@ -186,7 +186,7 @@ Reason=ImportError: No module named audioop
 Ignore=true
 
 [CPython.test_binhex]
-Ignore=true
+Ignore=true # blocked by https://github.com/IronLanguages/ironpython3/issues/673
 
 [CPython.test_builtin] # IronPython.test_builtin_stdlib
 Ignore=true
@@ -297,10 +297,6 @@ Ignore=true
 Ignore=true
 Reason=ImportError: Cannot import name SemLock
 
-[CPython.test_contextlib]
-Ignore=true
-Reason=Hangs
-
 [CPython.test_copy]
 IsolationLevel=ENGINE
 MaxRecursion=100
@@ -661,6 +657,7 @@ Ignore=true
 Reason=unittest.case.SkipTest: No module named 'nis'
 
 [CPython.test_nntplib]
+Ignore=true # currently failing in CI
 RunCondition=NOT $(IS_NETCOREAPP) # https://github.com/IronLanguages/ironpython3/issues/1058
 
 [CPython.test_normalization]

Tests/test_exceptions.py

@@ -87,11 +87,8 @@ def test_finally_continue_nested_finally_fails(self):
         finally:
             continue
 '''
-        try:
+        with self.assertRaises(SyntaxError):
             compile(t, '<test>', 'exec')
-            self.fail("Should raise SyntaxError")
-        except SyntaxError:
-            pass
 
     def test_bigint_division(self):
         def divide(a, b):
@@ -1046,4 +1043,28 @@ def f():
 
         self.assertRaises(error, f)
 
+    def test_reraise_context(self):
+        # reraising an exception should preserve the context
+        ex1 = Exception(1)
+        try:
+            try:
+                raise ex1
+            except:
+                raise ex1
+        except Exception as e:
+            self.assertIsNone(e.__context__)
+
+        ex1 = Exception(1)
+        ex2 = Exception(2)
+        try:
+            try:
+                try:
+                    raise ex2
+                except:
+                    raise ex1
+            except:
+                raise ex1
+        except Exception as e:
+            self.assertIs(e.__context__, ex2)
+
 run_test(__name__)