handle missing column aliases for composite types

aholmberg · aholmberg · commit bd1e7e7537a3 · 2016-07-20T10:52:32.000-05:00
This fixes some edge cases where some metadata goes missing in an upgrade from
C* 2.0 --&gt; 2.1.

PYTHON-562
diff --git a/cassandra/metadata.py b/cassandra/metadata.py
@@ -1777,12 +1777,9 @@ def _build_table_metadata(self, row, col_rows=None, trigger_rows=None):
             comparator = types.lookup_casstype(row["comparator"])
             table_meta.comparator = comparator
 
-            if issubclass(comparator, types.CompositeType):
-                column_name_types = comparator.subtypes
-                is_composite_comparator = True
-            else:
-                column_name_types = (comparator,)
-                is_composite_comparator = False
+            is_dct_comparator = issubclass(comparator, types.DynamicCompositeType)
+            is_composite_comparator = issubclass(comparator, types.CompositeType)
+            column_name_types = comparator.subtypes if is_composite_comparator else (comparator,)
 
             num_column_name_components = len(column_name_types)
             last_col = column_name_types[-1]
@@ -1796,7 +1793,8 @@ def _build_table_metadata(self, row, col_rows=None, trigger_rows=None):
 
             if column_aliases is not None:
                 column_aliases = json.loads(column_aliases)
-            else:
+
+            if not column_aliases:  # json load failed or column_aliases empty PYTHON-562
                 column_aliases = [r.get('column_name') for r in clustering_rows]
 
             if is_composite_comparator:
@@ -1819,10 +1817,10 @@ def _build_table_metadata(self, row, col_rows=None, trigger_rows=None):
 
                     # Some thrift tables define names in composite types (see PYTHON-192)
                     if not column_aliases and hasattr(comparator, 'fieldnames'):
-                        column_aliases = comparator.fieldnames
+                        column_aliases = filter(None, comparator.fieldnames)
             else:
                 is_compact = True
-                if column_aliases or not col_rows:
+                if column_aliases or not col_rows or is_dct_comparator:
                     has_value = True
                     clustering_size = num_column_name_components
                 else:
@@ -1867,7 +1865,7 @@ def _build_table_metadata(self, row, col_rows=None, trigger_rows=None):
                 if len(column_aliases) > i:
                     column_name = column_aliases[i]
                 else:
-                    column_name = "column%d" % i
+                    column_name = "column%d" % (i + 1)
 
                 data_type = column_name_types[i]
                 cql_type = _cql_from_cass_type(data_type)
