Issue #6676: Ensure a meaningful exception is raised when attempting

to parse more than one XML document per pyexpat xmlparser instance.
(Original patches by Hirokazu Yamamoto and Amaury Forgeot d'Arc, with
suggested wording by David Gutteridge)

diff --git a/Doc/library/pyexpat.rst b/Doc/library/pyexpat.rst
index 3d88d85d1cc9f61699caaa8ad421d4e88a193b38..cb8ab65d644647fdad09582bb36582b54a8d9ed8 100644 (file)
--- a/Doc/library/pyexpat.rst
+++ b/Doc/library/pyexpat.rst
@@ -100,6 +100,11 @@ The :mod:`xml.parsers.expat` module contains two functions:
       http://www.python.org/ns/ elem1
       elem2
 
+   Due to limitations in the ``Expat`` library used by :mod:`pyexpat`,
+   the :class:`xmlparser` instance returned can only be used to parse a single
+   XML document.  Call ``ParserCreate`` for each document to provide unique
+   parser instances.
+
 
 .. seealso::
 
@@ -119,7 +124,9 @@ XMLParser Objects
 
    Parses the contents of the string *data*, calling the appropriate handler
    functions to process the parsed data.  *isfinal* must be true on the final call
-   to this method.  *data* can be the empty string at any time.
+   to this method; it allows the parsing of a single file in fragments,
+   not the submission of multiple files.
+   *data* can be the empty string at any time.
 
 
 .. method:: xmlparser.ParseFile(file)

diff --git a/Lib/test/test_pyexpat.py b/Lib/test/test_pyexpat.py
index 8ef391791f717255d8876aaccecfb2846d86380c..95a614bb9b79a94bd4572118093d2c650c54c1da 100644 (file)
--- a/Lib/test/test_pyexpat.py
+++ b/Lib/test/test_pyexpat.py
@@ -236,6 +236,18 @@ class ParseTest(unittest.TestCase):
         operations = out.out
         self._verify_parse_output(operations)
 
+    def test_parse_again(self):
+        parser = expat.ParserCreate()
+        file = BytesIO(data)
+        parser.ParseFile(file)
+        # Issue 6676: ensure a meaningful exception is raised when attempting
+        # to parse more than one XML document per xmlparser instance,
+        # a limitation of the Expat library.
+        with self.assertRaises(expat.error) as cm:
+            parser.ParseFile(file)
+        self.assertEqual(expat.ErrorString(cm.exception.code),
+                          expat.errors.XML_ERROR_FINISHED)
+
 class NamespaceSeparatorTest(unittest.TestCase):
     def test_legal(self):
         # Tests that make sure we get errors when the namespace_separator value

diff --git a/Misc/NEWS b/Misc/NEWS
index 10ddd9a4bbe8b74500f55699959e14ed3ef6420d..5240f6997ff77113e76c3731b56e2a1f551a715b 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -89,6 +89,11 @@ Library
 - Issue #20817: Fix inspect.getcallargs() to fail correctly if more
   than 3 arguments are missing. Patch by Jeremiah Lowin.
 
+- Issue #6676: Ensure a meaningful exception is raised when attempting
+  to parse more than one XML document per pyexpat xmlparser instance.
+  (Original patches by Hirokazu Yamamoto and Amaury Forgeot d'Arc, with
+  suggested wording by David Gutteridge)
+
 Documentation
 -------------
 

diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index a71ecc530e4d6c09a5e788614ce5b034cc05286f..97f2b5677171a90da060ffbe3a6a46ebb06ed035 100644 (file)
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -908,7 +908,7 @@ xmlparse_ParseFile(xmlparseobject *self, PyObject *f)
         void *buf = XML_GetBuffer(self->itself, BUF_SIZE);
         if (buf == NULL) {
             Py_XDECREF(readmethod);
-            return PyErr_NoMemory();
+            return get_parse_result(self, 0);
         }
 
         bytes_read = readinst(buf, BUF_SIZE, readmethod);