We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
`ImapWidget` may call `keyring.get_password()` with `username=None`, violating API and potentially crashing it
### Issue description

The problematic code is:

https://github.com/qtile/qtile/blob/9ccaf6f1c01a9ffbd7beacdd8f405884bd81e1c0/libqtile/widget/imapwidget.py#L78

At this point, `self.user` may be `None`. However, according to the API definition at:

https://github.com/jaraco/keyring/blob/0cebfebbf516a47e4e45911ba6b4d4dd2699845c/keyring/core.py#L54

`keyring.get_password()` expects two `str` argument, i.e. `None` is not acceptable. If `keyrings-alt` backend is installed, then it explicitly crashes on `None` username:

```pytb
libqtile/widget/imapwidget.py:78: in __init__
    password = keyring.get_password("imapwidget", self.user)
.tox/py310-x11/lib/python3.10/site-packages/keyring/core.py:56: in get_password
    return get_keyring().get_password(service_name, username)
.tox/py310-x11/lib/python3.10/site-packages/keyrings/alt/file_base.py:92: in get_password
    assoc = self._generate_assoc(service, username)
.tox/py310-x11/lib/python3.10/site-packages/keyrings/alt/file_base.py:133: in _generate_assoc
    return (escape_for_ini(service) + r'\0' + escape_for_ini(username)).encode()
.tox/py310-x11/lib/python3.10/site-packages/keyrings/alt/escape.py:29: in escape
    return "".join(_escape_char(c) for c in value.encode('utf-8'))
E   AttributeError: 'NoneType' object has no attribute 'encode'
```

To reproduce:

```
tox -e py310-x11  # you can cancel the initial test run, after dependencies are installed
. .tox/py310-x11/bin/activate
pip install imapclient keyring keyrings-alt
pytest --backend=x11
```

### Version

0.23.1.dev83+g9ccaf6f1

### Backend

X11 (default)

### Config

_No response_

### Logs

_No response_

### Required

- [X] I have searched past issues to see if this bug has already been reported, and it hasn't been.
- [X] I understand that people give their precious time for free, and thus I've done my very best to make this problem as easy as possible to investigate.

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `libqtile/widget/imapwidget.py`
Content:
```
1 # -*- coding: utf-8 -*-
2 # Copyright (c) 2015 David R. Andersen
3 #
4 # Permission is hereby granted, free of charge, to any person obtaining a copy
5 # of this software and associated documentation files (the "Software"), to deal
6 # in the Software without restriction, including without limitation the rights
7 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 # copies of the Software, and to permit persons to whom the Software is
9 # furnished to do so, subject to the following conditions:
10 #
11 # The above copyright notice and this permission notice shall be included in
12 # all copies or substantial portions of the Software.
13 #
14 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20 # SOFTWARE.
21 
22 import imaplib
23 import re
24 
25 import keyring
26 
27 from libqtile.log_utils import logger
28 from libqtile.widget import base
29 
30 
31 class ImapWidget(base.ThreadPoolText):
32     """Email IMAP widget
33 
34     This widget will scan one of your imap email boxes and report the number of
35     unseen messages present.  I've configured it to only work with imap with
36     ssl. Your password is obtained from the Gnome Keyring.
37 
38     Writing your password to the keyring initially is as simple as (changing
39     out <userid> and <password> for your userid and password):
40 
41     1) create the file ~/.local/share/python_keyring/keyringrc.cfg with the
42        following contents::
43 
44            [backend]
45            default-keyring=keyring.backends.Gnome.Keyring
46            keyring-path=/home/<userid>/.local/share/keyring/
47 
48 
49     2) Execute the following python shell script once::
50 
51            #!/usr/bin/env python3
52            import keyring
53            user = <userid>
54            password = <password>
55            keyring.set_password('imapwidget', user, password)
56 
57     mbox names must include the path to the mbox (except for the default
58     INBOX).  So, for example if your mailroot is ``~/Maildir``, and you want to
59     look at the mailbox at HomeMail/fred, the mbox setting would be:
60     ``mbox="~/Maildir/HomeMail/fred"``.  Note the nested sets of quotes! Labels
61     can be whatever you choose, of course.
62 
63     Widget requirements: keyring_.
64 
65     .. _keyring: https://pypi.org/project/keyring/
66     """
67 
68     defaults = [
69         ("mbox", '"INBOX"', "mailbox to fetch"),
70         ("label", "INBOX", "label for display"),
71         ("user", None, "email username"),
72         ("server", None, "email server name"),
73     ]
74 
75     def __init__(self, **config):
76         base.ThreadPoolText.__init__(self, "", **config)
77         self.add_defaults(ImapWidget.defaults)
78         password = keyring.get_password("imapwidget", self.user)
79         if password is not None:
80             self.password = password
81         else:
82             logger.critical("Gnome Keyring Error")
83 
84     def poll(self):
85         im = imaplib.IMAP4_SSL(self.server, 993)
86         if self.password == "Gnome Keyring Error":
87             text = "Gnome Keyring Error"
88         else:
89             im.login(self.user, self.password)
90             status, response = im.status(self.mbox, "(UNSEEN)")
91             text = response[0].decode()
92             text = self.label + ": " + re.sub(r"\).*$", "", re.sub(r"^.*N\s", "", text))
93             im.logout()
94         return text
95
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/libqtile/widget/imapwidget.py b/libqtile/widget/imapwidget.py
--- a/libqtile/widget/imapwidget.py
+++ b/libqtile/widget/imapwidget.py
@@ -24,6 +24,7 @@
 
 import keyring
 
+from libqtile.confreader import ConfigError
 from libqtile.log_utils import logger
 from libqtile.widget import base
 
@@ -75,6 +76,8 @@
     def __init__(self, **config):
         base.ThreadPoolText.__init__(self, "", **config)
         self.add_defaults(ImapWidget.defaults)
+        if self.user is None:
+            raise ConfigError("You must set the 'user' parameter for the IMAP widget.")
         password = keyring.get_password("imapwidget", self.user)
         if password is not None:
             self.password = password

{"golden_diff": "diff --git a/libqtile/widget/imapwidget.py b/libqtile/widget/imapwidget.py\n--- a/libqtile/widget/imapwidget.py\n+++ b/libqtile/widget/imapwidget.py\n@@ -24,6 +24,7 @@\n \n import keyring\n \n+from libqtile.confreader import ConfigError\n from libqtile.log_utils import logger\n from libqtile.widget import base\n \n@@ -75,6 +76,8 @@\n     def __init__(self, **config):\n         base.ThreadPoolText.__init__(self, \"\", **config)\n         self.add_defaults(ImapWidget.defaults)\n+        if self.user is None:\n+            raise ConfigError(\"You must set the 'user' parameter for the IMAP widget.\")\n         password = keyring.get_password(\"imapwidget\", self.user)\n         if password is not None:\n             self.password = password\n", "issue": "`ImapWidget` may call `keyring.get_password()` with `username=None`, violating API and potentially crashing it\n### Issue description\n\nThe problematic code is:\r\n\r\nhttps://github.com/qtile/qtile/blob/9ccaf6f1c01a9ffbd7beacdd8f405884bd81e1c0/libqtile/widget/imapwidget.py#L78\r\n\r\nAt this point, `self.user` may be `None`. However, according to the API definition at:\r\n\r\nhttps://github.com/jaraco/keyring/blob/0cebfebbf516a47e4e45911ba6b4d4dd2699845c/keyring/core.py#L54\r\n\r\n`keyring.get_password()` expects two `str` argument, i.e. `None` is not acceptable. If `keyrings-alt` backend is installed, then it explicitly crashes on `None` username:\r\n\r\n```pytb\r\nlibqtile/widget/imapwidget.py:78: in __init__\r\n    password = keyring.get_password(\"imapwidget\", self.user)\r\n.tox/py310-x11/lib/python3.10/site-packages/keyring/core.py:56: in get_password\r\n    return get_keyring().get_password(service_name, username)\r\n.tox/py310-x11/lib/python3.10/site-packages/keyrings/alt/file_base.py:92: in get_password\r\n    assoc = self._generate_assoc(service, username)\r\n.tox/py310-x11/lib/python3.10/site-packages/keyrings/alt/file_base.py:133: in _generate_assoc\r\n    return (escape_for_ini(service) + r'\\0' + escape_for_ini(username)).encode()\r\n.tox/py310-x11/lib/python3.10/site-packages/keyrings/alt/escape.py:29: in escape\r\n    return \"\".join(_escape_char(c) for c in value.encode('utf-8'))\r\nE   AttributeError: 'NoneType' object has no attribute 'encode'\r\n```\r\n\r\nTo reproduce:\r\n\r\n```\r\ntox -e py310-x11  # you can cancel the initial test run, after dependencies are installed\r\n. .tox/py310-x11/bin/activate\r\npip install imapclient keyring keyrings-alt\r\npytest --backend=x11\r\n```\n\n### Version\n\n0.23.1.dev83+g9ccaf6f1\n\n### Backend\n\nX11 (default)\n\n### Config\n\n_No response_\n\n### Logs\n\n_No response_\n\n### Required\n\n- [X] I have searched past issues to see if this bug has already been reported, and it hasn't been.\n- [X] I understand that people give their precious time for free, and thus I've done my very best to make this problem as easy as possible to investigate.\n", "before_files": [{"content": "# -*- coding: utf-8 -*-\n# Copyright (c) 2015 David R. Andersen\n#\n# Permission is hereby granted, free of charge, to any person obtaining a copy\n# of this software and associated documentation files (the \"Software\"), to deal\n# in the Software without restriction, including without limitation the rights\n# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n# copies of the Software, and to permit persons to whom the Software is\n# furnished to do so, subject to the following conditions:\n#\n# The above copyright notice and this permission notice shall be included in\n# all copies or substantial portions of the Software.\n#\n# THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n# SOFTWARE.\n\nimport imaplib\nimport re\n\nimport keyring\n\nfrom libqtile.log_utils import logger\nfrom libqtile.widget import base\n\n\nclass ImapWidget(base.ThreadPoolText):\n    \"\"\"Email IMAP widget\n\n    This widget will scan one of your imap email boxes and report the number of\n    unseen messages present.  I've configured it to only work with imap with\n    ssl. Your password is obtained from the Gnome Keyring.\n\n    Writing your password to the keyring initially is as simple as (changing\n    out <userid> and <password> for your userid and password):\n\n    1) create the file ~/.local/share/python_keyring/keyringrc.cfg with the\n       following contents::\n\n           [backend]\n           default-keyring=keyring.backends.Gnome.Keyring\n           keyring-path=/home/<userid>/.local/share/keyring/\n\n\n    2) Execute the following python shell script once::\n\n           #!/usr/bin/env python3\n           import keyring\n           user = <userid>\n           password = <password>\n           keyring.set_password('imapwidget', user, password)\n\n    mbox names must include the path to the mbox (except for the default\n    INBOX).  So, for example if your mailroot is ``~/Maildir``, and you want to\n    look at the mailbox at HomeMail/fred, the mbox setting would be:\n    ``mbox=\"~/Maildir/HomeMail/fred\"``.  Note the nested sets of quotes! Labels\n    can be whatever you choose, of course.\n\n    Widget requirements: keyring_.\n\n    .. _keyring: https://pypi.org/project/keyring/\n    \"\"\"\n\n    defaults = [\n        (\"mbox\", '\"INBOX\"', \"mailbox to fetch\"),\n        (\"label\", \"INBOX\", \"label for display\"),\n        (\"user\", None, \"email username\"),\n        (\"server\", None, \"email server name\"),\n    ]\n\n    def __init__(self, **config):\n        base.ThreadPoolText.__init__(self, \"\", **config)\n        self.add_defaults(ImapWidget.defaults)\n        password = keyring.get_password(\"imapwidget\", self.user)\n        if password is not None:\n            self.password = password\n        else:\n            logger.critical(\"Gnome Keyring Error\")\n\n    def poll(self):\n        im = imaplib.IMAP4_SSL(self.server, 993)\n        if self.password == \"Gnome Keyring Error\":\n            text = \"Gnome Keyring Error\"\n        else:\n            im.login(self.user, self.password)\n            status, response = im.status(self.mbox, \"(UNSEEN)\")\n            text = response[0].decode()\n            text = self.label + \": \" + re.sub(r\"\\).*$\", \"\", re.sub(r\"^.*N\\s\", \"\", text))\n            im.logout()\n        return text\n", "path": "libqtile/widget/imapwidget.py"}], "after_files": [{"content": "# -*- coding: utf-8 -*-\n# Copyright (c) 2015 David R. Andersen\n#\n# Permission is hereby granted, free of charge, to any person obtaining a copy\n# of this software and associated documentation files (the \"Software\"), to deal\n# in the Software without restriction, including without limitation the rights\n# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n# copies of the Software, and to permit persons to whom the Software is\n# furnished to do so, subject to the following conditions:\n#\n# The above copyright notice and this permission notice shall be included in\n# all copies or substantial portions of the Software.\n#\n# THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n# SOFTWARE.\n\nimport imaplib\nimport re\n\nimport keyring\n\nfrom libqtile.confreader import ConfigError\nfrom libqtile.log_utils import logger\nfrom libqtile.widget import base\n\n\nclass ImapWidget(base.ThreadPoolText):\n    \"\"\"Email IMAP widget\n\n    This widget will scan one of your imap email boxes and report the number of\n    unseen messages present.  I've configured it to only work with imap with\n    ssl. Your password is obtained from the Gnome Keyring.\n\n    Writing your password to the keyring initially is as simple as (changing\n    out <userid> and <password> for your userid and password):\n\n    1) create the file ~/.local/share/python_keyring/keyringrc.cfg with the\n       following contents::\n\n           [backend]\n           default-keyring=keyring.backends.Gnome.Keyring\n           keyring-path=/home/<userid>/.local/share/keyring/\n\n\n    2) Execute the following python shell script once::\n\n           #!/usr/bin/env python3\n           import keyring\n           user = <userid>\n           password = <password>\n           keyring.set_password('imapwidget', user, password)\n\n    mbox names must include the path to the mbox (except for the default\n    INBOX).  So, for example if your mailroot is ``~/Maildir``, and you want to\n    look at the mailbox at HomeMail/fred, the mbox setting would be:\n    ``mbox=\"~/Maildir/HomeMail/fred\"``.  Note the nested sets of quotes! Labels\n    can be whatever you choose, of course.\n\n    Widget requirements: keyring_.\n\n    .. _keyring: https://pypi.org/project/keyring/\n    \"\"\"\n\n    defaults = [\n        (\"mbox\", '\"INBOX\"', \"mailbox to fetch\"),\n        (\"label\", \"INBOX\", \"label for display\"),\n        (\"user\", None, \"email username\"),\n        (\"server\", None, \"email server name\"),\n    ]\n\n    def __init__(self, **config):\n        base.ThreadPoolText.__init__(self, \"\", **config)\n        self.add_defaults(ImapWidget.defaults)\n        if self.user is None:\n            raise ConfigError(\"You must set the 'user' parameter for the IMAP widget.\")\n        password = keyring.get_password(\"imapwidget\", self.user)\n        if password is not None:\n            self.password = password\n        else:\n            logger.critical(\"Gnome Keyring Error\")\n\n    def poll(self):\n        im = imaplib.IMAP4_SSL(self.server, 993)\n        if self.password == \"Gnome Keyring Error\":\n            text = \"Gnome Keyring Error\"\n        else:\n            im.login(self.user, self.password)\n            status, response = im.status(self.mbox, \"(UNSEEN)\")\n            text = response[0].decode()\n            text = self.label + \": \" + re.sub(r\"\\).*$\", \"\", re.sub(r\"^.*N\\s\", \"\", text))\n            im.logout()\n        return text\n", "path": "libqtile/widget/imapwidget.py"}]}