fix!: persist other features when changing the community feature

changelog/705.bugfix.rst

@@ -0,0 +1 @@
+Fixed an issue where it would be possible to remove other features when enabling or disabling the ``COMMUNITY`` feature for a :class:`.Guild`.

disnake/guild.py

@@ -1975,16 +1975,28 @@ async def edit(
             fields["system_channel_flags"] = system_channel_flags.value
 
         if community is not MISSING:
-            features = []
-            if community:
-                if "rules_channel_id" in fields and "public_updates_channel_id" in fields:
-                    features.append("COMMUNITY")
+            # If we don't have complete feature information for the guild,
+            # it is possible to disable or enable other features that we didn't intend to touch.
+            # To enable or disable a feature, we will need to provide all of the existing features in advance.
+            if self.unavailable:
+                raise RuntimeError(
+                    "cannot modify features of an unavailable guild due to potentially destructive results."
+                )
+            features = set(self.features)
+            if community is not MISSING:
+                if not isinstance(community, bool):
+                    raise TypeError("community must be a bool instance")
+                if community:
+                    if "rules_channel_id" in fields and "public_updates_channel_id" in fields:
+                        features.add("COMMUNITY")
+                    else:
+                        raise ValueError(
+                            "community field requires both rules_channel and public_updates_channel fields to be provided"
+                        )
                 else:
-                    raise ValueError(
-                        "community field requires both rules_channel and public_updates_channel fields to be provided"
-                    )
+                    features.discard("COMMUNITY")
 
-            fields["features"] = features
+            fields["features"] = list(features)
 
         if premium_progress_bar_enabled is not MISSING:
             fields["premium_progress_bar_enabled"] = premium_progress_bar_enabled