Add tests for issue 51309

tests/unit/utils/test_filebuffer.py

@@ -9,11 +9,14 @@
 
 # Import Python libs
 from __future__ import absolute_import, unicode_literals, print_function
+import os
 
 # Import Salt Testing libs
 from tests.support.unit import TestCase
+from tests.support.helpers import generate_random_name
 
 # Import salt libs
+import salt.modules.cmdmod as cmdmod
 from salt.utils.filebuffer import BufferedReader, InvalidFileMode
 
 
@@ -30,3 +33,26 @@ class TestFileBuffer(TestCase):
 
         with self.assertRaises(InvalidFileMode):
             BufferedReader('/tmp/foo', mode='wb')
+
+    def test_issue_51309(self):
+        '''
+        https://github.com/saltstack/salt/issues/51309
+        '''
+        temp_name = os.path.join(os.environ.get('TEMP'),
+                                 generate_random_name(prefix='salt-test-'))
+        cmd = 'tzutil /l > {0}'.format(temp_name)
+        cmdmod.run(cmd=cmd, python_shell=True)
+
+        def find_value(text):
+            stripped_text = text.strip()
+            try:
+                with BufferedReader(temp_name) as breader:
+                    for chunk in breader:
+                        if stripped_text in chunk:
+                            return True
+                return False
+            except (IOError, OSError):
+                return False
+
+        self.assertTrue(find_value('(UTC) Coordinated Universal Time'))
+        os.remove(temp_name)