Error from editing plot settings in a plot

[GuiMacielPereira]

Original reporter: James Cresswell

Describe the bug
Hiding curves in the settings dialog in a plot caused an error:

  File "/opt/mantidworkbenchnightly/lib/python3.10/site-packages/mantidqt/widgets/plotconfigdialog/presenter.py", line 75, in apply_properties
    tab.apply_properties()
  File "/opt/mantidworkbenchnightly/lib/python3.10/site-packages/mantidqt/widgets/plotconfigdialog/curvestabwidget/presenter.py", line 65, in apply_properties
    self._replot_current_curve(plot_kwargs)
  File "/opt/mantidworkbenchnightly/lib/python3.10/site-packages/mantidqt/widgets/plotconfigdialog/curvestabwidget/presenter.py", line 153, in _replot_current_curve
    ax.add_line(lines_to_remove.pop())
IndexError: pop from empty list

To Reproduce
I asked the user for the data he used and he sent me this folder:
MantidTroubleshooting.zip

The script generated from the faulty plot was the following:

# import mantid algorithms, numpy and matplotlib
from mantid.simpleapi import *
import matplotlib.pyplot as plt
import numpy as np


import matplotlib.pyplot as plt
from mantid.plots.utility import MantidAxType
from mantid.api import AnalysisDataService as ADS

IvsQ_74306_74307_74308 = ADS.retrieve('IvsQ_74306_74307_74308')
IvsQ_74374_74375_74376 = ADS.retrieve('IvsQ_74374_74375_74376')
IvsQ_74324_74325_74326 = ADS.retrieve('IvsQ_74324_74325_74326')
IvsQ_74388_74389 = ADS.retrieve('IvsQ_74388_74389')
IvsQ_74342_74343_74344 = ADS.retrieve('IvsQ_74342_74343_74344')

fig, axes = plt.subplots(edgecolor='#ffffff', num='S12 MS024', subplot_kw={'projection': 'mantid'})
axes.errorbar(IvsQ_74342_74343_74344, capsize=1.0, color='#1f77b4', elinewidth=1.0, label='IvsQ_74342_74343_74344: spec 330', linewidth=1.0, marker='.', markersize=4.0, wkspIndex=0)
axes.errorbar(IvsQ_74324_74325_74326, capsize=1.0, color='#ff7f0e', elinewidth=1.0, label='IvsQ_74324_74325_74326: spec 330', linewidth=1.0, marker='.', markersize=4.0, wkspIndex=0)
axes.errorbar(IvsQ_74306_74307_74308, capsize=1.0, color='#2ca02c', elinewidth=1.0, label='IvsQ_74306_74307_74308: spec 330', linewidth=1.0, marker='.', markersize=4.0, wkspIndex=0)
axes.errorbar(IvsQ_74388_74389, capsize=1.0, color='#e377c2', elinewidth=1.0, label='S12 Si PET MS024 Rinse Lipid Air IvsQ_74388_74389: spec 330', linewidth=1.0, marker='.', markersize=4.0, wkspIndex=0)
axes.errorbar(IvsQ_74374_74375_74376, capsize=1.0, color='#d62728', elinewidth=1.0, label='IvsQ_74374_74375_74376: spec 330', linewidth=1.0, marker='.', markersize=4.0, wkspIndex=0)
axes.minorticks_on()
axes.tick_params(axis='x', which='minor', **{'gridOn': False, 'tick1On': True, 'tick2On': False, 'label1On': True, 'label2On': False, 'size': 0, 'tickdir': 'out', 'width': 1})
axes.tick_params(axis='y', which='minor', **{'gridOn': False, 'tick1On': True, 'tick2On': False, 'label1On': True, 'label2On': False, 'size': 0, 'tickdir': 'out', 'width': 1})
axes.tick_params(axis='x', which='major', **{'gridOn': True, 'tick1On': True, 'tick2On': False, 'label1On': True, 'label2On': False, 'size': 6, 'tickdir': 'out', 'width': 1})
axes.tick_params(axis='y', which='major', **{'gridOn': True, 'tick1On': True, 'tick2On': False, 'label1On': True, 'label2On': False, 'size': 6, 'tickdir': 'out', 'width': 1})
axes.set_title('S12 MS024')
axes.set_xlabel('q ($\\AA^{-1}$)')
axes.set_ylabel('Reflectivity')
axes.set_xlim([0.0079686, 0.39723])
axes.set_ylim([0.0, 3.4784])
axes.set_xscale('log')
axes.set_yscale('log')
legend = axes.legend(fontsize=8.0).set_draggable(True).legend

fig.show()
# Use plt.show() if running the script outside of Workbench
#plt.show()
# Scripting Plots in Mantid:
# https://docs.mantidproject.org/tutorials/python_in_mantid/plotting/02_scripting_plots.html

Then open the plot options dialog.
Select the second or the third curve and click Apply. You should get an error.
If you select and deselect other curves, you should also get an error sometimes.

Expected behavior
No error when selecting or deselecting other curves.
No change of behaviour when changes are applied but nothing was changed in the plotconfigdialog

Screenshots

Platform/Version (please complete the following information):

• OS: Rocky Linux 8.9 (Green Obsidian)
• Mantid Version 6.9.20240425.1854

[sf1919]

Is this happening in earlier versions of Mantid?

[GuiMacielPereira]

I tested it and it's not present in 6.8, it appeared in 6.9

[sf1919]

In that case I think we'd best sort it out as a bugfix for v6.10 as it looks pretty small.

[jhaigh0]

I recognise that line of code as something I had to change with the mpl update, so probably introduced the problem there.