From 261fa2901e6c90a43596ac9107d66d0e3e8f7036 Mon Sep 17 00:00:00 2001
From: Eric Snow <ericsnowcurrently@gmail.com>
Date: Wed, 19 Jul 2023 13:45:42 -0600
Subject: [PATCH 1/2] Don't always clear the interned state for a string.

---
 Objects/unicodeobject.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index f543c0a65b49f6..e8e8cab99c8140 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -14818,6 +14818,7 @@ _PyUnicode_ClearInterned(PyInterpreterState *interp)
     PyObject *s, *ignored_value;
     while (PyDict_Next(interned, &pos, &s, &ignored_value)) {
         assert(PyUnicode_IS_READY(s));
+        int shared = 0;
         switch (PyUnicode_CHECK_INTERNED(s)) {
         case SSTATE_INTERNED_IMMORTAL:
             // Skip the Immortal Instance check and restore
@@ -14829,6 +14830,14 @@ _PyUnicode_ClearInterned(PyInterpreterState *interp)
 #endif
             break;
         case SSTATE_INTERNED_IMMORTAL_STATIC:
+            /* It is shared between interpreters, so we should unmark it
+               only when this is the last interpreter in which it's
+               interned.  We immortalize all the statically initialized
+               strings during startup, so we can rely on the
+               main interpreter to be the last one. */
+            if (!_Py_IsMainInterpreter(interp)) {
+                shared = 1;
+            }
             break;
         case SSTATE_INTERNED_MORTAL:
             /* fall through */
@@ -14837,7 +14846,9 @@ _PyUnicode_ClearInterned(PyInterpreterState *interp)
         default:
             Py_UNREACHABLE();
         }
-        _PyUnicode_STATE(s).interned = SSTATE_NOT_INTERNED;
+        if (!shared) {
+            _PyUnicode_STATE(s).interned = SSTATE_NOT_INTERNED;
+        }
     }
 #ifdef INTERNED_STATS
     fprintf(stderr,

From eeb53e775ff077ee35d8d2c10dd6c24315190765 Mon Sep 17 00:00:00 2001
From: Eric Snow <ericsnowcurrently@gmail.com>
Date: Thu, 20 Jul 2023 15:16:10 -0600
Subject: [PATCH 2/2] Add a NEWS entry.

---
 .../2023-07-20-15-15-57.gh-issue-105699.DdqHFg.rst             | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-07-20-15-15-57.gh-issue-105699.DdqHFg.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-07-20-15-15-57.gh-issue-105699.DdqHFg.rst b/Misc/NEWS.d/next/Core and Builtins/2023-07-20-15-15-57.gh-issue-105699.DdqHFg.rst
new file mode 100644
index 00000000000000..4a257c6282220f
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-07-20-15-15-57.gh-issue-105699.DdqHFg.rst	
@@ -0,0 +1,3 @@
+Python no longer crashes due an infrequent race when initialzing
+per-interpreter interned strings.  The crash would manifest when the
+interpreter was finalized.