Array module's buffer interface can now handle empty arrays.

rhettinger · rhettinger · commit 17d76210f8ec · 2007-04-02T22:54:21.000Z
diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py
@@ -601,6 +601,13 @@ def test_bug_817234(self):
         self.assertEqual(iter.next().span(), (4, 4))
         self.assertRaises(StopIteration, iter.next)
 
+    def test_empty_array(self):
+        # SF buf 1647541
+        import array
+        for typecode in 'cbBuhHiIlLfd':
+            a = array.array(typecode)
+            self.assertEqual(re.compile("bla").match(a), None)
+            self.assertEqual(re.compile("").match(a).groups(), ())            
 
 def run_re_tests():
     from test.re_tests import benchmarks, tests, SUCCEED, FAIL, SYNTAX_ERROR
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
@@ -1745,6 +1745,8 @@ static PyMappingMethods array_as_mapping = {
 	(objobjargproc)array_ass_subscr
 };
 
+static const void *emptybuf = "";
+
 static Py_ssize_t
 array_buffer_getreadbuf(arrayobject *self, Py_ssize_t index, const void **ptr)
 {
@@ -1754,6 +1756,8 @@ array_buffer_getreadbuf(arrayobject *self, Py_ssize_t index, const void **ptr)
 		return -1;
 	}
 	*ptr = (void *)self->ob_item;
+	if (*ptr == NULL)
+		*ptr = emptybuf;
 	return self->ob_size*self->ob_descr->itemsize;
 }
 
@@ -1766,6 +1770,8 @@ array_buffer_getwritebuf(arrayobject *self, Py_ssize_t index, const void **ptr)
 		return -1;
 	}
 	*ptr = (void *)self->ob_item;
+	if (*ptr == NULL)
+		*ptr = emptybuf;
 	return self->ob_size*self->ob_descr->itemsize;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1745,6 +1745,8 @@ static PyMappingMethods array_as_mapping = {`
`1745`	`1745`	`(objobjargproc)array_ass_subscr`
`1746`	`1746`	`};`
`1747`	`1747`
	`1748`	`+static const void *emptybuf = "";`
	`1749`	`+`
`1748`	`1750`	`static Py_ssize_t`
`1749`	`1751`	`array_buffer_getreadbuf(arrayobject self, Py_ssize_t index, const void *ptr)`
`1750`	`1752`	`{`
`@@ -1754,6 +1756,8 @@ array_buffer_getreadbuf(arrayobject self, Py_ssize_t index, const void *ptr)`
`1754`	`1756`	`return -1;`
`1755`	`1757`	`}`
`1756`	`1758`	`ptr = (void )self->ob_item;`
	`1759`	`+ if (*ptr == NULL)`
	`1760`	`+ *ptr = emptybuf;`
`1757`	`1761`	`return self->ob_size*self->ob_descr->itemsize;`
`1758`	`1762`	`}`
`1759`	`1763`
`@@ -1766,6 +1770,8 @@ array_buffer_getwritebuf(arrayobject self, Py_ssize_t index, const void *ptr)`
`1766`	`1770`	`return -1;`
`1767`	`1771`	`}`
`1768`	`1772`	`ptr = (void )self->ob_item;`
	`1773`	`+ if (*ptr == NULL)`
	`1774`	`+ *ptr = emptybuf;`
`1769`	`1775`	`return self->ob_size*self->ob_descr->itemsize;`
`1770`	`1776`	`}`
`1771`	`1777`