bpo-42882: _PyRuntimeState_Init() leaves unicode next_index unchanged (GH-24193)

Fix the _PyUnicode_FromId() function (_Py_IDENTIFIER(var) API) when
Py_Initialize() / Py_Finalize() is called multiple times:
preserve _PyRuntime.unicode_ids.next_index value.

Use _PyRuntimeState_INIT macro instead memset(0) to reset
_PyRuntimeState members to zero.

1 files changed, 4 insertions, 0 deletions

diff --git a/Include/internal/pycore_runtime.h b/Include/internal/pycore_runtime.h
index 8c54abbb069..bcd710c4496 100644
--- a/Include/internal/pycore_runtime.h
+++ b/Include/internal/pycore_runtime.h
@@ -51,6 +51,8 @@ typedef struct _Py_AuditHookEntry {
 
 struct _Py_unicode_runtime_ids {
     PyThread_type_lock lock;
+    // next_index value must be preserved when Py_Initialize()/Py_Finalize()
+    // is called multiple times: see _PyUnicode_FromId() implementation.
     Py_ssize_t next_index;
 };
 
@@ -107,6 +109,8 @@ typedef struct pyruntimestate {
 
     PyPreConfig preconfig;
 
+    // Audit values must be preserved when Py_Initialize()/Py_Finalize()
+    // is called multiple times.
     Py_OpenCodeHookFunction open_code_hook;
     void *open_code_userdata;
     _Py_AuditHookEntry *audit_hook_head;