fix: Fix 88a4e45, which changed default version to None instead of ''…

… for consistency

scrapyd/sqlite.py

@@ -46,6 +46,9 @@ def __len__(self):
     def __iter__(self):
         yield from self.iterkeys()
 
+    def __repr__(self):
+        return f"JsonSqliteDict({dict(self.iteritems())})"
+
     def iterkeys(self):
         sql = f"SELECT key FROM {self.table}"
         return (self.decode(row[0]) for row in self.conn.execute(sql))

scrapyd/utils.py

@@ -53,6 +53,9 @@ def __getitem__(self, key):
     def __setitem__(self, key, value):
         self.cache_manager[key] = value
 
+    def __repr__(self):
+        return f"UtilsCache(cache_manager={self.cache_manager!r})"
+
 
 def get_spider_queues(config):
     """Return a dict of Spider Queues keyed by project name"""
@@ -125,6 +128,12 @@ def get_crawl_args(message):
 
 def get_spider_list(project, runner=None, pythonpath=None, version=None):
     """Return the spider list from the given project, using the given runner"""
+
+    # UtilsCache uses JsonSqliteDict, which encodes the project's value as JSON, but JSON allows only string keys,
+    # so the stored dict will have a "null" key, instead of a None key.
+    if version is None:
+        version = ""
+
     if "cache" not in get_spider_list.__dict__:
         get_spider_list.cache = UtilsCache()
     try: