gh-113655: Reduce recursion limit to a safe number for Windows

Author: mdboom

Include/cpython/pystate.h

@@ -227,7 +227,7 @@ struct _ts {
 #  define Py_C_RECURSION_LIMIT 1200
 #else
    // This value is duplicated in Lib/test/support/__init__.py
-#  define Py_C_RECURSION_LIMIT 8000
+#  define Py_C_RECURSION_LIMIT 4000
 #endif
 
 

Lib/test/support/__init__.py

@@ -2377,7 +2377,7 @@ def _get_c_recursion_limit():
         return _testcapi.Py_C_RECURSION_LIMIT
     except (ImportError, AttributeError):
         # Originally taken from Include/cpython/pystate.h .
-        return 8000
+        return 4000
 
 # The default C recursion limit.
 Py_C_RECURSION_LIMIT = _get_c_recursion_limit()

Lib/test/test_functools.py

@@ -1876,7 +1876,7 @@ def fib(n):
 
         if not support.Py_DEBUG:
             with support.infinite_recursion():
-                fib(2500)
+                fib(1250)
 
 
 @py_functools.lru_cache()