Repository: spyder-ide/spyder

Issue:
AttributeError when closing main window
## Description

### What steps will reproduce the problem?

<!--- You can use Markdown here --->

make a clean install of spyder via conda, then press ctrl+q to quit

### Traceback
```python-traceback
Traceback (most recent call last):
  File "/home/nic/anaconda3/lib/python3.9/site-packages/spyder/app/mainwindow.py", line 1477, in moveEvent
    if not self.isMaximized() and not self.layouts.get_fullscreen_flag():
AttributeError: 'NoneType' object has no attribute 'get_fullscreen_flag'
```

## Versions

* Spyder version: 5.2.2 
* Python version: 3.9.12
* Qt version: 5.15.2
* PyQt5 version: 5.15.7
* Operating System: Linux 5.15.0-46-generic

### Dependencies

```
# Mandatory:
atomicwrites >=1.2.0          :  1.4.0 (OK)
chardet >=2.0.0               :  4.0.0 (OK)
cloudpickle >=0.5.0           :  2.0.0 (OK)
cookiecutter >=1.6.0          :  1.7.3 (OK)
diff_match_patch >=20181111   :  20200713 (OK)
intervaltree >=3.0.2          :  3.1.0 (OK)
IPython >=7.6.0;<8.0.0        :  7.31.1 (OK)
jedi >=0.17.2;<0.19.0         :  0.18.1 (OK)
jellyfish >=0.7               :  0.9.0 (OK)
jsonschema >=3.2.0            :  4.4.0 (OK)
keyring >=17.0.0              :  23.4.0 (OK)
nbconvert >=4.0               :  6.4.4 (OK)
numpydoc >=0.6.0              :  1.4.0 (OK)
parso >=0.7.0;<0.9.0          :  0.8.3 (OK)
pexpect >=4.4.0               :  4.8.0 (OK)
pickleshare >=0.4             :  0.7.5 (OK)
psutil >=5.3                  :  5.9.0 (OK)
pygments >=2.0                :  2.11.2 (OK)
pylint >=2.5.0                :  2.14.5 (OK)
pyls_spyder >=0.4.0           :  0.4.0 (OK)
pylsp >=1.3.2;<1.4.0          :  1.3.3 (OK)
pylsp_black >=1.0.0           :  1.0.0 (OK)
qdarkstyle =3.0.2             :  3.0.2 (OK)
qstylizer >=0.1.10            :  0.1.10 (OK)
qtawesome >=1.0.2             :  1.0.3 (OK)
qtconsole >=5.2.1;<5.3.0      :  5.2.2 (OK)
qtpy >=1.5.0                  :  2.0.1 (OK)
rtree >=0.9.7                 :  0.9.7 (OK)
setuptools >=49.6.0           :  63.4.1 (OK)
sphinx >=0.6.6                :  5.0.2 (OK)
spyder_kernels >=2.2.1;<2.3.0 :  2.2.1 (OK)
textdistance >=4.2.0          :  4.2.1 (OK)
three_merge >=0.1.1           :  0.1.1 (OK)
watchdog >=0.10.3             :  2.1.6 (OK)
xdg >=0.26                    :  0.27 (OK)
zmq >=17                      :  23.2.0 (OK)

# Optional:
cython >=0.21                 :  None (NOK)
matplotlib >=2.0.0            :  None (NOK)
numpy >=1.7                   :  None (OK)
pandas >=1.1.1                :  None (NOK)
scipy >=0.17.0                :  None (NOK)
sympy >=0.7.3                 :  None (NOK)
```



Discussion:
Hey @n4kzzz, thanks for reporting. We'll fix this error in our next version (5.3.3), to be released next week.

Resolving patch:
diff --git a/spyder/app/mainwindow.py b/spyder/app/mainwindow.py
--- a/spyder/app/mainwindow.py
+++ b/spyder/app/mainwindow.py
@@ -1289,7 +1289,7 @@ def resizeEvent(self, event):
 
     def moveEvent(self, event):
         """Reimplement Qt method"""
-        if hasattr(self, 'layouts'):
+        if hasattr(self, 'layouts') and self.layouts is not None:
             if (
                 not self.isMaximized()
                 and not self.layouts.get_fullscreen_flag()


Test patch: