Flexible SQL columns have TEXT affinity

Reverts 2314f0f9ff

Also implements handling of text values for the base `Type` and
overwrites in the blob-based `PathType`

beets/dbcore/db.py

@@ -724,7 +724,7 @@ class Database(object):
                     id INTEGER PRIMARY KEY,
                     entity_id INTEGER,
                     key TEXT,
-                    value NONE,
+                    value TEXT,
                     UNIQUE(entity_id, key) ON CONFLICT REPLACE);
                 CREATE INDEX IF NOT EXISTS {0}_by_entity
                     ON {0} (entity_id);

beets/dbcore/types.py

@@ -93,12 +93,16 @@ class Type(object):
         http://www.sqlite.org/datatype3.html
         https://docs.python.org/2/library/sqlite3.html#sqlite-and-python-types
 
-        Flexible fields have the type afinity `NULL`. This means the
-        `sql_value` may be of any type returned by the database adapter.
-        Since the schema might change it is advisable that this method
-        handles all of them.
+        Flexible fields have the type afinity `TEXT`. This means the
+        `sql_value` is either a `buffer` or a `unicode` object` and the
+        method must handle these in addition.
         """
-        return self.normalize(sql_value)
+        if isinstance(sql_value, buffer):
+            sql_value = bytes(sql_value).decode('utf8', 'ignore')
+        if isinstance(sql_value, unicode):
+            return self.parse(sql_value)
+        else:
+            return self.normalize(sql_value)
 
     def to_sql(self, model_value):
         """Convert a value as stored in the model object to a value used

beets/library.py

@@ -108,6 +108,9 @@ class PathType(types.Type):
         else:
             return value
 
+    def from_sql(self, sql_value):
+        return self.normalize(sql_value)
+
     def to_sql(self, value):
         if isinstance(value, str):
             value = buffer(value)