[GR-70280] Fix remaining tests for except*.

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_except_star.txt

@@ -47,6 +47,7 @@ test.test_except_star.TestExceptStarSplitSemantics.test_singleton_groups_are_kep
 test.test_except_star.TestExceptStar_WeirdExceptionGroupSubclass.test_catch_all_unhashable_exception_group_subclass @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_except_star.TestExceptStar_WeirdExceptionGroupSubclass.test_catch_none_unhashable_exception_group_subclass @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_except_star.TestExceptStar_WeirdExceptionGroupSubclass.test_catch_some_unhashable_exception_group_subclass @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
+test.test_except_star.TestExceptStar_WeirdExceptionGroupSubclass.test_reraise_unhashable_eg @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_except_star.TestExceptStar_WeirdLeafExceptions.test_catch_everything_unhashable_leaf @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_except_star.TestExceptStar_WeirdLeafExceptions.test_catch_nothing_unhashable_leaf @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_except_star.TestExceptStar_WeirdLeafExceptions.test_catch_unhashable_leaf_exception @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/exception/BaseExceptionGroupBuiltins.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -51,7 +51,10 @@
 import static com.oracle.graal.python.util.PythonUtils.tsLiteral;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.IdentityHashMap;
 import java.util.List;
+import java.util.Set;
 
 import com.oracle.graal.python.PythonLanguage;
 import com.oracle.graal.python.annotations.Builtin;
@@ -299,6 +302,44 @@ private static PBaseExceptionGroup subset(Node inliningTarget, PBaseExceptionGro
         return eg;
     }
 
+    /**
+     * Build the sub-exception group of {@code orig} that contains all leaf exceptions also present
+     * in {@code keep}. This corresponds to CPython's {@code exception_group_projection()} helper.
+     */
+    @TruffleBoundary
+    public static PBaseExceptionGroup exceptionGroupProjection(Node inliningTarget, PBaseExceptionGroup orig, Object[] keep) {
+        Set<Object> leafExceptions = Collections.newSetFromMap(new IdentityHashMap<>());
+        for (Object exception : keep) {
+            collectExceptionGroupLeafIdentities(exception, leafExceptions);
+        }
+        return exceptionGroupProjection(inliningTarget, orig, leafExceptions);
+    }
+
+    private static void collectExceptionGroupLeafIdentities(Object exception, Set<Object> leafExceptions) {
+        if (exception instanceof PBaseExceptionGroup group) {
+            for (Object child : group.getExceptions()) {
+                collectExceptionGroupLeafIdentities(child, leafExceptions);
+            }
+        } else if (exception != PNone.NONE) {
+            leafExceptions.add(exception);
+        }
+    }
+
+    private static PBaseExceptionGroup exceptionGroupProjection(Node inliningTarget, PBaseExceptionGroup orig, Set<Object> leafExceptions) {
+        List<Object> matches = new ArrayList<>();
+        for (Object exception : orig.getExceptions()) {
+            if (exception instanceof PBaseExceptionGroup group) {
+                PBaseExceptionGroup projected = exceptionGroupProjection(inliningTarget, group, leafExceptions);
+                if (projected != null) {
+                    matches.add(projected);
+                }
+            } else if (leafExceptions.contains(exception)) {
+                matches.add(exception);
+            }
+        }
+        return subset(inliningTarget, orig, matches.toArray());
+    }
+
     private enum MatcherType {
         BY_TYPE,
         BY_PREDICATE,

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/exception/EncapsulateExceptionGroupNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -42,6 +42,7 @@
 
 import com.oracle.graal.python.PythonLanguage;
 import com.oracle.graal.python.builtins.objects.PNone;
+import com.oracle.graal.python.builtins.objects.exception.BaseExceptionGroupBuiltins;
 import com.oracle.graal.python.builtins.objects.exception.PBaseException;
 import com.oracle.graal.python.builtins.objects.exception.PBaseExceptionGroup;
 import com.oracle.graal.python.lib.PyObjectCallMethodObjArgs;
@@ -102,9 +103,7 @@ public static Object matchExceptions(VirtualFrame frame,
                     if (isBaseExceptionGroupProfile.profile(inliningTarget, exceptionObj instanceof PBaseExceptionGroup)) {
                         PBaseExceptionGroup group = (PBaseExceptionGroup) exceptionObj;
                         if (groupContainsReraisesProfile.profile(inliningTarget, group.getContainsReraises())) {
-                            for (Object e : group.getExceptions()) {
-                                reraisedUnhandledExceptions.add(e);
-                            }
+                            reraisedUnhandledExceptions.add(group);
                         } else {
                             exceptionGroupList.add(group);
                         }
@@ -117,12 +116,8 @@ public static Object matchExceptions(VirtualFrame frame,
                 return PException.fromExceptionInfo(exceptionGroup, PythonOptions.isPExceptionWithJavaStacktrace(language));
             }
             if (reraisedOrUnhandledSizeProfile.profile(inliningTarget, reraisedUnhandledExceptions.size() != 0)) {
-                PBaseExceptionGroup reraisedGroup = (PBaseExceptionGroup) deriveExceptionGroup.execute(
-                                frame,
-                                inliningTarget,
-                                exceptionOrigUnreified,
-                                T_DERIVE,
-                                PFactory.createTuple(language, reraisedUnhandledExceptions.toArray(new Object[0])));
+                PBaseExceptionGroup reraisedGroup = BaseExceptionGroupBuiltins.exceptionGroupProjection(
+                                inliningTarget, (PBaseExceptionGroup) exceptionOrigUnreified, reraisedUnhandledExceptions.toArray(new Object[0]));
                 reraisedGroup.setParent(exceptionGroup.getParent());
                 exceptionGroupList.add(reraisedGroup);
             }