Do not use attribute width as computed width and restore computed width on reset

If the attribute width (which is the user width) is used as computed width, on
reset of the widths the custom widths are still in used.

tryton/tryton/gui/window/view_form/view/list.py

@@ -455,11 +455,11 @@ class TreeXMLViewParser(XMLViewParser):
 
         screen = self.view.screen
         width = screen.tree_column_width[screen.model_name].get(column.name)
-        if not width:
-            if 'width' in attributes:
-                computed_width = width = int(attributes['width'])
-            else:
-                width = computed_width
+        if width or attributes.get('width'):
+            if not width:
+                width = int(attributes['width'])
+        else:
+            width = computed_width
         column.width = width
         column.computed_width = computed_width
         if width > 0:
@@ -619,6 +619,7 @@ class ViewTree(View):
         for col in self.treeview.get_columns():
             if col.name:
                 col.set_fixed_width(col.computed_width)
+                col.width = col.computed_width
 
     def get_column_widget(self, column):
         'Return the widget of the column'