Fix creation of IdentifierData in config raw methods (#3829)

* Fix creation of IdentifierData in config

Also adds some new tests regarding partial primary keys.

Resolves #3796.

Signed-off-by: Toby Harradine <tobyharradine@gmail.com>
Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

redbot/core/config.py

@@ -334,7 +334,7 @@ class Group(Value):
         """
         is_group = self.is_group(item)
         is_value = not is_group and self.is_value(item)
-        new_identifiers = self.identifier_data.add_identifier(item)
+        new_identifiers = self.identifier_data.get_child(item)
         if is_group:
             return Group(
                 identifier_data=new_identifiers,
@@ -381,7 +381,7 @@ class Group(Value):
             dict access. These are casted to `str` for you.
         """
         path = tuple(str(p) for p in nested_path)
-        identifier_data = self.identifier_data.add_identifier(*path)
+        identifier_data = self.identifier_data.get_child(*path)
         await self.driver.clear(identifier_data)
 
     def is_group(self, item: Any) -> bool:
@@ -499,7 +499,7 @@ class Group(Value):
             else:
                 default = poss_default
 
-        identifier_data = self.identifier_data.add_identifier(*path)
+        identifier_data = self.identifier_data.get_child(*path)
         try:
             raw = await self.driver.get(identifier_data)
         except KeyError:
@@ -583,7 +583,7 @@ class Group(Value):
             The value to store.
         """
         path = tuple(str(p) for p in nested_path)
-        identifier_data = self.identifier_data.add_identifier(*path)
+        identifier_data = self.identifier_data.get_child(*path)
         if isinstance(value, dict):
             value = _str_key_dict(value)
         await self.driver.set(identifier_data, value=value)

redbot/core/drivers/base.py

@@ -109,6 +109,28 @@ class IdentifierData:
     def __hash__(self) -> int:
         return hash((self.uuid, self.category, self.primary_key, self.identifiers))
 
+    def get_child(self, *keys: str) -> "IdentifierData":
+        if not all(isinstance(i, str) for i in keys):
+            raise ValueError("Identifiers must be strings.")
+
+        primary_keys = self.primary_key
+        identifiers = self.identifiers
+        num_missing_pkeys = self.primary_key_len - len(self.primary_key)
+        if num_missing_pkeys > 0:
+            primary_keys += keys[:num_missing_pkeys]
+        if len(keys) > num_missing_pkeys:
+            identifiers += keys[num_missing_pkeys:]
+
+        return IdentifierData(
+            self.cog_name,
+            self.uuid,
+            self.category,
+            primary_keys,
+            identifiers,
+            self.primary_key_len,
+            self.is_custom,
+        )
+
     def add_identifier(self, *identifier: str) -> "IdentifierData":
         if not all(isinstance(i, str) for i in identifier):
             raise ValueError("Identifiers must be strings.")