Repository: spyder-ide/spyder

Issue:
AttributeError when closing console
## Description

### What steps will reproduce the problem?

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Close console, forces you to send an issue report for some reason.

### Traceback
```python-traceback
Traceback (most recent call last):
  File "C:\Program Files\pkgs\spyder\plugins\ipythonconsole\plugin.py", line 1309, in close_client
    client.close()
  File "C:\Program Files\pkgs\spyder\plugins\ipythonconsole\widgets\client.py", line 577, in close
    self.get_kernel() is None or self.slave)
  File "C:\Program Files\pkgs\spyder\plugins\ipythonconsole\widgets\shell.py", line 164, in will_close
    self.spyder_kernel_comm.close()
  File "C:\Program Files\pkgs\spyder\plugins\ipythonconsole\comms\kernelcomm.py", line 144, in close
    self.shutdown_comm_channel()
  File "C:\Program Files\pkgs\spyder\plugins\ipythonconsole\comms\kernelcomm.py", line 87, in shutdown_comm_channel
    channel = self.kernel_client.comm_channel
AttributeError: 'NoneType' object has no attribute 'comm_channel'
```

## Versions

* Spyder version: 5.0.3 
* Python version: 3.7.9
* Qt version: 5.12.10
* PyQt5 version: 5.12.3
* Operating System: Windows 10

### Dependencies

```

# Mandatory:
atomicwrites >=1.2.0          :  1.4.0 (OK)
chardet >=2.0.0               :  4.0.0 (OK)
cloudpickle >=0.5.0           :  1.6.0 (OK)
cookiecutter >=1.6.0          :  1.7.3 (OK)
diff_match_patch >=20181111   :  20200713 (OK)
intervaltree                  :  None (OK)
IPython >=7.6.0               :  7.23.1 (OK)
jedi =0.17.2                  :  0.17.2 (OK)
jsonschema >=3.2.0            :  3.2.0 (OK)
keyring >=17.0.0              :  23.0.1 (OK)
nbconvert >=4.0               :  6.0.7 (OK)
numpydoc >=0.6.0              :  1.1.0 (OK)
paramiko >=2.4.0              :  2.7.2 (OK)
parso =0.7.0                  :  0.7.0 (OK)
pexpect >=4.4.0               :  4.8.0 (OK)
pickleshare >=0.4             :  0.7.5 (OK)
psutil >=5.3                  :  5.8.0 (OK)
pygments >=2.0                :  2.9.0 (OK)
pylint >=1.0                  :  2.8.2 (OK)
pyls >=0.36.2;<1.0.0          :  0.36.2 (OK)
pyls_black >=0.4.6            :  0.4.6 (OK)
pyls_spyder >=0.3.2;<0.4.0    :  0.3.2 (OK)
qdarkstyle =3.0.2             :  3.0.2 (OK)
qstylizer >=0.1.10            :  0.2.0 (OK)
qtawesome >=1.0.2             :  1.0.2 (OK)
qtconsole >=5.1.0             :  5.1.0 (OK)
qtpy >=1.5.0                  :  1.9.0 (OK)
rtree >=0.9.7                 :  0.9.7 (OK)
setuptools >=39.0.0           :  56.2.0 (OK)
sphinx >=0.6.6                :  3.5.4 (OK)
spyder_kernels >=2.0.3;<2.1.0 :  2.0.3 (OK)
textdistance >=4.2.0          :  4.2.1 (OK)
three_merge >=0.1.1           :  0.1.1 (OK)
watchdog                      :  1.0.2 (OK)
zmq >=17                      :  22.0.3 (OK)

# Optional:
cython >=0.21                 :  0.29.23 (OK)
matplotlib >=2.0.0            :  3.4.2 (OK)
numpy >=1.7                   :  1.19.3 (OK)
pandas >=1.1.1                :  1.2.4 (OK)
scipy >=0.17.0                :  1.6.3 (OK)
sympy >=0.7.3                 :  1.8 (OK)
```



Discussion:
Hi @c0dezer019,

Did you installed 5.0.3 with the installers or by the conda-forge channel?
@c0dezer019, is the console working well for you? 

Resolving patch:
diff --git a/spyder/plugins/ipythonconsole/comms/kernelcomm.py b/spyder/plugins/ipythonconsole/comms/kernelcomm.py
--- a/spyder/plugins/ipythonconsole/comms/kernelcomm.py
+++ b/spyder/plugins/ipythonconsole/comms/kernelcomm.py
@@ -84,7 +84,13 @@ def _set_comm_port(self, port):
 
     def shutdown_comm_channel(self):
         """Shutdown the comm channel."""
-        channel = self.kernel_client.comm_channel
+        # This is necessary to avoid an error when closing the console.
+        # Fixes spyder-ide/spyder#15645
+        try:
+            channel = self.kernel_client.comm_channel
+        except AttributeError:
+            channel = None
+
         if channel:
             id_list = self.get_comm_id_list()
             for comm_id in id_list:


Test patch: