Merge pull request #35497 from mantidproject/35495_error_bars_from_sc…

…ript

Fix for bug error bars plot options crash

docs/source/release/v6.7.0/Workbench/Bugfixes/35495.rst

@@ -0,0 +1 @@
+- Fixed bug where opening the plot options for a script-created plot with error bars, would crash Workbench.

qt/python/mantidqt/mantidqt/widgets/plotconfigdialog/curvestabwidget/__init__.py

@@ -231,7 +231,7 @@ def _get_errorbars_props_from_curve(curve, props):
         try:
             barlines = curve[2][0]
             props["errorevery"] = int(barlines.axes.creation_args[len(barlines.axes.creation_args) - 1]["errorevery"])
-        except (IndexError, TypeError, KeyError):
+        except (IndexError, TypeError, KeyError, AttributeError):
             props["errorevery"] = 1
         try:
             caps = curve[1]

qt/python/mantidqt/mantidqt/widgets/plotconfigdialog/curvestabwidget/test/test_curveproperties.py

@@ -7,6 +7,7 @@
 #  This file is part of the mantid workbench.
 
 import unittest
+import numpy as np
 from matplotlib import use as mpl_use
 
 mpl_use("Agg")  # noqa
@@ -120,3 +121,17 @@ def test_curve_hidden_on_errorbar_container(self):
         # Now hide connecting line
         container[0].set_visible(False)
         self.assertTrue(funcs.curve_hidden(container))
+
+    def test_error_bars_with_no_creation_args_are_handled(self):
+        fig = figure()
+        x = np.arange(10)
+        y = 2.5 * np.sin(x / 20 * np.pi)
+        yerr = np.linspace(0.05, 0.2, 10)
+        ax = fig.add_subplot()
+        ax.errorbar(x, y, yerr=yerr)
+
+        try:
+            CurveProperties.from_curve(ax.get_lines()[0])
+            CurveProperties.from_curve(ax.containers[0])
+        except RuntimeError:
+            self.fail()