[#3124|GTKUI] Fix comparing Name str if value is None

The original fix was not correct as the strcoll function cannot
accept None only strings. This fix ensures that the value is an
empty string if None for comparison.

deluge/ui/gtkui/torrentview.py

@@ -30,17 +30,17 @@ CTRL_ALT_MASK = CONTROL_MASK | MOD1_MASK
 
 
 def str_nocase_sort(model, iter1, iter2, data):
-    """
-    Sort string column data with locale.strcoll which (allegedly) uses ISO 14651.
+    """Sort string column data using ISO 14651 in lowercase.
+
+    Uses locale.strcoll which (allegedly) uses ISO 14651. Compares first
+    value with second and returns -1, 0, 1 for where it should be placed.
 
     """
-    try:
-        v1 = model[iter1][data].lower()
-        v2 = model[iter2][data].lower()
-    except AttributeError:
-        # Catch None type for value.
-        v1 = model[iter1][data]
-        v2 = model[iter2][data]
+    v1 = model[iter1][data]
+    v2 = model[iter2][data]
+    # Catch any values of None from model.
+    v1 = v1.lower() if v1 else ''
+    v2 = v2.lower() if v2 else ''
     return strcoll(v1, v2)