Issue #18408: Fix _PyUnicodeWriter_Finish(): clear writer->buffer,

vstinner · vstinner · commit 15a0bd396584 · 2013-07-08T22:29:55.000+02:00
so _PyUnicodeWriter_Dealloc() can be called on the writer after finish.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
@@ -13157,6 +13157,7 @@ _PyUnicodeWriter_WriteCstr(_PyUnicodeWriter *writer, const char *str, Py_ssize_t
 PyObject *
 _PyUnicodeWriter_Finish(_PyUnicodeWriter *writer)
 {
+    PyObject *str;
     if (writer->pos == 0) {
         Py_XDECREF(writer->buffer);
         _Py_RETURN_UNICODE_EMPTY();
@@ -13174,8 +13175,10 @@ _PyUnicodeWriter_Finish(_PyUnicodeWriter *writer)
         }
         writer->buffer = newbuffer;
     }
-    assert(_PyUnicode_CheckConsistency(writer->buffer, 1));
-    return unicode_result_ready(writer->buffer);
+    str = writer->buffer;
+    writer->buffer = NULL;
+    assert(_PyUnicode_CheckConsistency(str, 1));
+    return unicode_result_ready(str);
 }
 
 void

Original file line number	Diff line number	Diff line change
`@@ -13157,6 +13157,7 @@ _PyUnicodeWriter_WriteCstr(_PyUnicodeWriter writer, const char str, Py_ssize_t`
`13157`	`13157`	`PyObject *`
`13158`	`13158`	`_PyUnicodeWriter_Finish(_PyUnicodeWriter *writer)`
`13159`	`13159`	`{`
	`13160`	`+ PyObject *str;`
`13160`	`13161`	`if (writer->pos == 0) {`
`13161`	`13162`	`Py_XDECREF(writer->buffer);`
`13162`	`13163`	`_Py_RETURN_UNICODE_EMPTY();`
`@@ -13174,8 +13175,10 @@ _PyUnicodeWriter_Finish(_PyUnicodeWriter *writer)`
`13174`	`13175`	`}`
`13175`	`13176`	`writer->buffer = newbuffer;`
`13176`	`13177`	`}`
`13177`		`- assert(_PyUnicode_CheckConsistency(writer->buffer, 1));`
`13178`		`- return unicode_result_ready(writer->buffer);`
	`13178`	`+ str = writer->buffer;`
	`13179`	`+ writer->buffer = NULL;`
	`13180`	`+ assert(_PyUnicode_CheckConsistency(str, 1));`
	`13181`	`+ return unicode_result_ready(str);`
`13179`	`13182`	`}`
`13180`	`13183`
`13181`	`13184`	`void`