From 0d7dc8377418a0a27570c86f4fc55b06afef17b7 Mon Sep 17 00:00:00 2001
From: jakkdl <h6+github@pm.me>
Date: Tue, 2 Dec 2025 16:56:20 +0100
Subject: [PATCH 1/4] don't crash if exceptiongroup has only hidden tb frames

---
 src/_pytest/_code/code.py    | 8 +++++++-
 testing/code/test_excinfo.py | 9 +++++----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/_pytest/_code/code.py b/src/_pytest/_code/code.py
index add2a493ca7..4cf99a77340 100644
--- a/src/_pytest/_code/code.py
+++ b/src/_pytest/_code/code.py
@@ -1193,9 +1193,15 @@ def repr_excinfo(self, excinfo: ExceptionInfo[BaseException]) -> ExceptionChainR
                         format_exception(
                             type(excinfo.value),
                             excinfo.value,
-                            traceback[0]._rawentry,
+                            traceback[0]._rawentry if traceback else None,
                         )
                     )
+                    if not traceback:
+                        reprtraceback.extraline = (
+                            "All traceback entries are hidden. "
+                            "Pass `--full-trace` to see hidden and internal frames."
+                        )
+
                 else:
                     reprtraceback = self.repr_traceback(excinfo_)
                 reprcrash = excinfo_._getreprcrash()
diff --git a/testing/code/test_excinfo.py b/testing/code/test_excinfo.py
index 476720f0bbe..89040fb1efa 100644
--- a/testing/code/test_excinfo.py
+++ b/testing/code/test_excinfo.py
@@ -1897,19 +1897,20 @@ def test_nested_multiple() -> None:
 
 
 @pytest.mark.parametrize("tbstyle", ("long", "short", "auto", "line", "native"))
-def test_all_entries_hidden(pytester: Pytester, tbstyle: str) -> None:
+@pytest.mark.parametrize("group", (True, False))
+def test_all_entries_hidden(pytester: Pytester, tbstyle: str, group: bool) -> None:
     """Regression test for #10903."""
     pytester.makepyfile(
-        """
+        f"""
         def test():
             __tracebackhide__ = True
-            1 / 0
+            raise {'ExceptionGroup("", [ValueError("bar")])' if group else 'ValueError("bar")'}
     """
     )
     result = pytester.runpytest("--tb", tbstyle)
     assert result.ret == 1
     if tbstyle != "line":
-        result.stdout.fnmatch_lines(["*ZeroDivisionError: division by zero"])
+        result.stdout.fnmatch_lines(["*ValueError: bar"])
     if tbstyle not in ("line", "native"):
         result.stdout.fnmatch_lines(["All traceback entries are hidden.*"])
 

From 5e75d3a07c31863d7fa8d67dfb17c745099eca98 Mon Sep 17 00:00:00 2001
From: jakkdl <h6+github@pm.me>
Date: Tue, 2 Dec 2025 17:10:09 +0100
Subject: [PATCH 2/4] add newsfragment

---
 changelog/13734.bugfix.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog/13734.bugfix.rst

diff --git a/changelog/13734.bugfix.rst b/changelog/13734.bugfix.rst
new file mode 100644
index 00000000000..de1d7368cd4
--- /dev/null
+++ b/changelog/13734.bugfix.rst
@@ -0,0 +1 @@
+Fixed crash when a test raises an exceptiongroup with ``__tracebackhide__ = True``.

From 32a6eb4cd1e672e49a0dad0969cb745edec9cbde Mon Sep 17 00:00:00 2001
From: jakkdl <h6+github@pm.me>
Date: Tue, 2 Dec 2025 17:11:47 +0100
Subject: [PATCH 3/4] fix py<3.11

---
 testing/code/test_excinfo.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/testing/code/test_excinfo.py b/testing/code/test_excinfo.py
index 89040fb1efa..919c1c73770 100644
--- a/testing/code/test_excinfo.py
+++ b/testing/code/test_excinfo.py
@@ -1902,6 +1902,9 @@ def test_all_entries_hidden(pytester: Pytester, tbstyle: str, group: bool) -> No
     """Regression test for #10903."""
     pytester.makepyfile(
         f"""
+        import sys
+        if sys.version_info < (3, 11):
+            from exceptiongroup import ExceptionGroup
         def test():
             __tracebackhide__ = True
             raise {'ExceptionGroup("", [ValueError("bar")])' if group else 'ValueError("bar")'}

From b2b3d06f1b5221dc1faabed7be97509d4fb54523 Mon Sep 17 00:00:00 2001
From: jakkdl <h6+github@pm.me>
Date: Tue, 2 Dec 2025 18:29:00 +0100
Subject: [PATCH 4/4] add param ids

---
 testing/code/test_excinfo.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testing/code/test_excinfo.py b/testing/code/test_excinfo.py
index 919c1c73770..70499fec893 100644
--- a/testing/code/test_excinfo.py
+++ b/testing/code/test_excinfo.py
@@ -1897,7 +1897,7 @@ def test_nested_multiple() -> None:
 
 
 @pytest.mark.parametrize("tbstyle", ("long", "short", "auto", "line", "native"))
-@pytest.mark.parametrize("group", (True, False))
+@pytest.mark.parametrize("group", (True, False), ids=("group", "bare"))
 def test_all_entries_hidden(pytester: Pytester, tbstyle: str, group: bool) -> None:
     """Regression test for #10903."""
     pytester.makepyfile(