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

[Berker Peksag]

https://github.com/python/cpython/commit/4b3042900e7e8dc120408bab86642c09c9d25a5a
commit: 4b3042900e7e8dc120408bab86642c09c9d25a5a
branch: 3.6
author: Berker Peksag <berker.peksag at gmail.com>
committer: GitHub <noreply at github.com>
date: 2017-11-23T17:33:12+03:00
summary:

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

(cherry picked from commit bdb8315c21825487b54852ff0511fb4881ea2181)

files:
A Misc/NEWS.d/next/Windows/2017-11-19-09-46-27.bpo-1102.NY-g1F.rst
M Lib/test/test_msilib.py
M PC/_msi.c

diff --git a/Lib/test/test_msilib.py b/Lib/test/test_msilib.py
index f656f7234e2..aa19883ac6f 100644
--- 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
new file mode 100644
index 00000000000..6a6618e9692
--- /dev/null
+++ 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
index 2ab7e731a1e..eab39d9b002 100644
--- 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);
 }