errors related to surface-cap model

[Elaine Meng]

I don't understand the underlying reason, but after turning off front-clipping, I get an error turning it on again, and another trying to close (all) after that:

open 3e8t
surface
clip front 0
clip front off
clip front 0

Error processing trigger "frame drawn"
Traceback (most recent call last):
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/triggerset.py", line 126, in invoke
return self._func(self._name, data)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/model_panel/tool.py", line 126, in _fill_tree
model_id, model_id_string, bg_color, display, name = self._get_info(model)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/model_panel/tool.py", line 180, in _get_info
bg_color = self._model_color(obj)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/model_panel/tool.py", line 207, in _model_color
return model.single_color
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/models.py", line 81, in _get_single_color
return self.color if self.vertex_colors is None else None
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/graphics/drawing.py", line 451, in get_color
return self._colors[0]
TypeError: 'NoneType' object is not subscriptable

.... and then when I try to close:
close
Traceback (most recent call last):
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/cmd_line/tool.py", line 178, in execute
cmd.run(cmd_text)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/cli.py", line 2366, in run
result = ci.function(session, kw_args)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/close.py", line 32, in close
m.close(cmodels)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/models.py", line 347, in close
self.remove(models)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/models.py", line 339, in remove
parent.remove_drawing(model, delete=False)
File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/graphics/drawing.py", line 239, in remove_drawing
self._child_drawings.remove(d)
ValueError: list.remove(x): x not in list

ValueError: list.remove(x): x not in list

File "/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/graphics/drawing.py", line 239, in remove_drawing
self._child_drawings.remove(d)

[Tom Goddard]

Fixed.

Code that delete clipping caps had not been updated to handle the that clip caps are now models.