Blender crash after F8, F5, x

Created by: portnov

Problem statement

Blender crashes after certain sequence of actions

Steps to reproduce

Create two nodes and connect them. For example, NGon + ViewerDraw.
Execute "reload scripts"
Execute "update NodeTree" (F5)
Remove the first node (NGon) (x)

Expected result

Just usual recalculation of the tree

Actual result

Blender crashes.

bpy.ops.node.sv_add_svngonnode(type="SvNGonNode", use_transform=True)  # Operator
bpy.ops.node.translate_attach_remove_on_cancel(TRANSFORM_OT_translate={"value":(552.499, 209.291, 0), "orient_type":'GLOBAL', "orient_matrix":((1, 0, 0), (0, 1, 0), (0, 0, 1)), "orient_matrix_type":'GLOBAL', "constraint_axis":(False, False, False), "mirror":True, "use_proportional_edit":False, "proportional_edit_falloff":'SMOOTH', "proportional_size":1, "use_proportional_connected":False, "use_proportional_projected":False, "snap":False, "snap_target":'CLOSEST', "snap_point":(0, 0, 0), "snap_align":False, "snap_normal":(0, 0, 0), "gpencil_strokes":False, "cursor_transform":False, "texture_space":False, "remove_on_cancel":True, "release_confirm":False, "use_accurate":False}, NODE_OT_attach={}, NODE_OT_insert_offset={})  # Operator
bpy.context.scene.sv_selected_category = 'SVERCHOK_Analyzers'  # Property
bpy.ops.node.sv_add_svareanode(type="SvAreaNode", use_transform=True)  # Operator
bpy.ops.node.translate_attach_remove_on_cancel(TRANSFORM_OT_translate={"value":(772.399, 106.979, 0), "orient_type":'GLOBAL', "orient_matrix":((1, 0, 0), (0, 1, 0), (0, 0, 1)), "orient_matrix_type":'GLOBAL', "constraint_axis":(False, False, False), "mirror":True, "use_proportional_edit":False, "proportional_edit_falloff":'SMOOTH', "proportional_size":1, "use_proportional_connected":False, "use_proportional_projected":False, "snap":False, "snap_target":'CLOSEST', "snap_point":(0, 0, 0), "snap_align":False, "snap_normal":(0, 0, 0), "gpencil_strokes":False, "cursor_transform":False, "texture_space":False, "remove_on_cancel":True, "release_confirm":False, "use_accurate":False}, NODE_OT_attach={}, NODE_OT_insert_offset={})  # Operator
bpy.ops.node.select(wait_to_deselect_others=True, mouse_x=642, mouse_y=322, extend=False, deselect_all=True)  # Operator
bpy.ops.node.link(detach=False)  # Operator
bpy.ops.node.select(wait_to_deselect_others=True, mouse_x=639, mouse_y=281, extend=False, deselect_all=True)  # Operator
bpy.ops.node.link(detach=False)  # Operator
bpy.ops.node.sverchok_update_context()  # Operator

# backtrace
./blender(BLI_system_backtrace+0x1d) [0x6fbcb2d]
./blender() [0x1657f69]
/lib/x86_64-linux-gnu/libc.so.6(+0x378e0) [0x7f51ea0be8e0]
./blender(rna_ensure_property+0) [0x1a30db0]
./blender(RNA_property_collection_lookup_string+0x1e) [0x1a3697e]
./blender(RNA_struct_find_property+0x2d) [0x1a36b6d]
./blender() [0x1b485ab]
./blender(_PyEval_EvalFrameDefault+0x4ef3) [0x16501e3]
./blender(_PyEval_EvalCodeWithName+0xadc) [0x5df9b3c]
./blender(_PyFunction_FastCallKeywords+0xa6) [0x5d47c26]
./blender(_PyEval_EvalFrameDefault+0x8cce) [0x1653fbe]
./blender() [0x164a240]
./blender(_PyEval_EvalFrameDefault+0x8cce) [0x1653fbe]
./blender() [0x164a240]
./blender(_PyEval_EvalFrameDefault+0x88dc) [0x1653bcc]
./blender() [0x164a240]
./blender(_PyFunction_FastCallDict+0x2a6) [0x5d47b66]
./blender() [0x1b4772e]
./blender() [0x1ab4d17]
./blender(ntreeUpdateTree+0xa7) [0x16de6e7]
./blender() [0x1ee1fca]
./blender() [0x182046b]
./blender() [0x1822b47]
./blender() [0x18237e0]
./blender() [0x18252ec]
./blender(wm_event_do_handlers+0x4f5) [0x1825ba5]
./blender(WM_main+0x20) [0x181bbe0]
./blender(main+0x317) [0x159e5b7]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xeb) [0x7f51ea0ab09b]
./blender() [0x165481c]

Sverchok version

Current master, Blender 2.82 (sub 7).