Clarify two comments

Author: gpshead

Lib/test/test_tcl.py

@@ -589,7 +589,8 @@ def test_passing_deeply_nested(self):
     def test_returning_deeply_nested(self):
         if not self.wantobjects:
             self.skipTest('requires wantobjects')
-        # The interpreter can only be used in the thread that created it.
+        # run_with_limited_c_stack() runs the test in a new thread, and a
+        # Tcl interpreter can only be used in the thread that created it.
         interp = Tcl()
         interp.eval('set x a; for {set i 0} {$i < %d} {incr i} {set x [list $x]}'
                     % support.exceeds_recursion_limit())

Modules/_tkinter.c

@@ -1078,7 +1078,9 @@ TupleAsObj(PyObject *value, int wrapped, int depth)
     for (Py_ssize_t i = 0; i < size; i++) {
         Tcl_Obj *item = AsObjNested(PyTuple_GET_ITEM(value, i), depth + 1);
         if (item == NULL) {
-            /* Release the already converted items. */
+            /* Free the already converted items.  A new Tcl object has a
+               zero reference count, so it must be acquired before it can
+               be released. */
             while (--i >= 0) {
                 Tcl_IncrRefCount(argv[i]);
                 Tcl_DecrRefCount(argv[i]);