Code cells not properly executed from splitted editors or new window editors

Issue Report Checklist

• Searched the issues page for similar reports
• Read the relevant sections of the Spyder Troubleshooting Guide and followed its advice
• Reproduced the issue after updating with conda update spyder (or pip, if not using Anaconda)
• Could not reproduce inside jupyter qtconsole (if console-related)
• Tried basic troubleshooting (if a bug/error)
  • Restarted Spyder
  • Reset preferences with spyder --reset
  • Reinstalled the latest version of Anaconda
  • Tried the other applicable steps from the Troubleshooting Guide
• Completed the Problem Description, Steps to Reproduce and Version sections below

Problem Description

The behaviour is:

- the editor shows a red line above each occurence of #%%
- press Ctrl-Enter in any cell N
- console shows runcell(0,...
- the whole file runs as if no cells were defined

What steps reproduce the problem?

It appears to happen randomly in different files, but can also be reproduced more reliably when a second editor window is opened. The malfunction (sofar) always happened in the new window.

What is the expected output? What do you see instead?

See above

Paste Traceback/Error Below (if applicable)

n/a

Versions

• Spyder version: 4.1.2 (problem first noticed a few months ago already)
• Python version: 3.7.2 64b
• Qt version: 5.9.6
• PyQt version: 5.9.2
• Operating System name/version: Win7 64b

Dependencies

# Mandatory:
atomicwrites >=1.2.0           :  1.2.1 (OK)
chardet >=2.0.0                :  3.0.4 (OK)
cloudpickle >=0.5.0            :  0.6.1 (OK)
diff_match_patch >=20181111    :  20181111 (OK)
intervaltree                   :  None (OK)
IPython >=4.0                  :  7.2.0 (OK)
jedi =0.15.2                   :  0.15.2 (OK)
nbconvert >=4.0                :  5.3.1 (OK)
numpydoc >=0.6.0               :  0.8.0 (OK)
paramiko >=2.4.0               :  2.4.2 (OK)
parso =0.5.2                   :  0.5.2 (OK)
pexpect >=4.4.0                :  4.7.0 (OK)
pickleshare >=0.4              :  0.7.5 (OK)
psutil >=5.3                   :  5.4.8 (OK)
pygments >=2.0                 :  2.3.1 (OK)
pylint >=0.25                  :  2.2.2 (OK)
pyls >=0.31.9;<0.32.0          :  0.31.9 (OK)
qdarkstyle >=2.8               :  2.8 (OK)
qtawesome >=0.5.7              :  0.5.7 (OK)
qtconsole >=4.6.0              :  4.6.0 (OK)
qtpy >=1.5.0                   :  1.5.2 (OK)
rtree >=0.8.3                  :  0.8.3 (OK)
sphinx >=0.6.6                 :  1.8.2 (OK)
spyder_kernels >=1.9.0;<1.10.0 :  1.9.0 (OK)
watchdog                       :  None (OK)
zmq >=17                       :  17.1.2 (OK)

# Optional:
cython >=0.21                  :  0.29.2 (OK)
matplotlib >=2.0.0             :  3.0.2 (OK)
numpy >=1.7                    :  1.15.4 (OK)
pandas >=0.13.1                :  0.24.2 (OK)
scipy >=0.17.0                 :  1.2.1 (OK)
sympy >=0.7.3                  :  1.3 (OK)

[impact27]

Should be fixed in https://github.com/spyder-ide/spyder/pull/12713

[steff456]

Thanks @impact27 !!