bpo-1102: View.Fetch() now returns None when it's exhausted (GH-4459)

berkerpeksag · web-flow · commit 4b3042900e7e · 2017-11-23T17:33:12.000+03:00
(cherry picked from commit bdb8315)
diff --git a/Lib/test/test_msilib.py b/Lib/test/test_msilib.py
@@ -1,7 +1,45 @@
 """ Test suite for the code in msilib """
 import unittest
-from test.support import import_module
+from test.support import TESTFN, import_module, unlink
 msilib = import_module('msilib')
+import msilib.schema
+
+
+def init_database():
+    path = TESTFN + '.msi'
+    db = msilib.init_database(
+        path,
+        msilib.schema,
+        'Python Tests',
+        'product_code',
+        '1.0',
+        'PSF',
+    )
+    return db, path
+
+
+class MsiDatabaseTestCase(unittest.TestCase):
+
+    def test_view_fetch_returns_none(self):
+        db, db_path = init_database()
+        properties = []
+        view = db.OpenView('SELECT Property, Value FROM Property')
+        view.Execute(None)
+        while True:
+            record = view.Fetch()
+            if record is None:
+                break
+            properties.append(record.GetString(1))
+        view.Close()
+        self.assertEqual(
+            properties,
+            [
+                'ProductName', 'ProductCode', 'ProductVersion',
+                'Manufacturer', 'ProductLanguage',
+            ]
+        )
+        self.addCleanup(unlink, db_path)
+
 
 class Test_make_id(unittest.TestCase):
     #http://msdn.microsoft.com/en-us/library/aa369212(v=vs.85).aspx
diff --git a/Misc/NEWS.d/next/Windows/2017-11-19-09-46-27.bpo-1102.NY-g1F.rst b/Misc/NEWS.d/next/Windows/2017-11-19-09-46-27.bpo-1102.NY-g1F.rst
@@ -0,0 +1,4 @@
+Return ``None`` when ``View.Fetch()`` returns ``ERROR_NO_MORE_ITEMS``
+instead of raising ``MSIError``.
+
+Initial patch by Anthony Tuininga.
diff --git a/PC/_msi.c b/PC/_msi.c
@@ -729,8 +729,12 @@ view_fetch(msiobj *view, PyObject*args)
     int status;
     MSIHANDLE result;
 
-    if ((status = MsiViewFetch(view->h, &result)) != ERROR_SUCCESS)
+    status = MsiViewFetch(view->h, &result);
+    if (status == ERROR_NO_MORE_ITEMS) {
+        Py_RETURN_NONE;
+    } else if (status != ERROR_SUCCESS) {
         return msierror(status);
+    }
 
     return record_new(result);
 }
