just return toplevel symbol table rather than all blocks (closes #19393)

Lib/symtable.py

@@ -10,10 +10,7 @@ import weakref
 __all__ = ["symtable", "SymbolTable", "Class", "Function", "Symbol"]
 
 def symtable(code, filename, compile_type):
-    raw = _symtable.symtable(code, filename, compile_type)
-    for top in raw.values():
-        if top.name == 'top':
-            break
+    top = _symtable.symtable(code, filename, compile_type)
     return _newSymbolTable(top, filename)
 
 class SymbolTableFactory:

Misc/NEWS

@@ -81,6 +81,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #19393: Fix symtable.symtable function to not be confused when there are
+  functions or classes named "top".
+
 - Issue #19339: telnetlib module is now using time.monotonic() when available
   to compute timeout.
 

Modules/symtablemodule.c

@@ -32,7 +32,7 @@ symtable_symtable(PyObject *self, PyObject *args)
     st = Py_SymtableString(str, filename, start);
     if (st == NULL)
         return NULL;
-    t = st->st_blocks;
+    t = (PyObject *)st->st_top;
     Py_INCREF(t);
     PyMem_Free((void *)st->st_future);
     PySymtable_Free(st);