[MM-42400] Prevent making groups with reserved names (#21040)

api4/group_test.go

@@ -154,6 +154,16 @@ func TestCreateGroup(t *testing.T) {
 	require.Error(t, err)
 	CheckBadRequestStatus(t, response)
 
+	reservedNameGroup := &model.Group{
+		DisplayName:    "dn_" + model.NewId(),
+		Name:           model.NewString("here"),
+		Source:         model.GroupSourceCustom,
+		AllowReference: true,
+	}
+	_, response, err = th.SystemAdminClient.CreateGroup(reservedNameGroup)
+	require.Error(t, err)
+	CheckBadRequestStatus(t, response)
+
 	th.SystemAdminClient.Logout()
 	_, response, err = th.SystemAdminClient.CreateGroup(g)
 	require.Error(t, err)
@@ -294,6 +304,12 @@ func TestPatchGroup(t *testing.T) {
 	CheckOKStatus(t, response)
 	require.Equal(t, true, patchedG2.AllowReference)
 
+	_, response, err = th.SystemAdminClient.PatchGroup(g2.Id, &model.GroupPatch{
+		Name: model.NewString("here"),
+	})
+	require.Error(t, err)
+	CheckBadRequestStatus(t, response)
+
 	th.SystemAdminClient.Logout()
 	_, response, err = th.SystemAdminClient.PatchGroup(group.Id, gp)
 	require.Error(t, err)

i18n/en.json

@@ -8643,6 +8643,10 @@
     "id": "model.group.name.invalid_length.app_error",
     "translation": "Name must be 1 to 64 lowercase alphanumeric characters."
   },
+  {
+    "id": "model.group.name.reserved_name.app_error",
+    "translation": "group name already exists as a reserved name"
+  },
   {
     "id": "model.group.remote_id.app_error",
     "translation": "invalid remote id property for group."

model/group.go

@@ -218,6 +218,10 @@ func (group *Group) IsValidName() *AppError {
 			return NewAppError("Group.IsValidName", "model.group.name.invalid_length.app_error", map[string]any{"GroupNameMaxLength": GroupNameMaxLength}, "", http.StatusBadRequest)
 		}
 
+		if *group.Name == UserNotifyAll || *group.Name == ChannelMentionsNotifyProp || *group.Name == UserNotifyHere {
+			return NewAppError("IsValidName", "model.group.name.reserved_name.app_error", nil, "", http.StatusBadRequest)
+		}
+
 		if !validGroupnameChars.MatchString(*group.Name) {
 			return NewAppError("Group.IsValidName", "model.group.name.invalid_chars.app_error", nil, "", http.StatusBadRequest)
 		}