Error on empty group/host name (#42584)

* error on false host/group name

(cherry picked from commit 12a8363fae)

changelogs/fragments/empty_gh_error.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+    - emtpy host/group name is an error https://github.com/ansible/ansible/issues/42044

lib/ansible/inventory/data.py

@@ -161,6 +161,7 @@ class InventoryData(object):
     def add_group(self, group):
         ''' adds a group to inventory if not there already '''
 
+        if group:
             if group not in self.groups:
                 g = Group(group)
                 self.groups[group] = g
@@ -168,6 +169,8 @@ class InventoryData(object):
                 display.debug("Added group %s to inventory" % group)
             else:
                 display.debug("group %s already in inventory" % group)
+        else:
+            raise AnsibleError("Invalid empty/false group name provided: %s" % group)
 
     def remove_group(self, group):
 
@@ -183,6 +186,7 @@ class InventoryData(object):
     def add_host(self, host, group=None, port=None):
         ''' adds a host to inventory and possibly a group if not there already '''
 
+        if host:
             g = None
             if group:
                 if group in self.groups:
@@ -215,6 +219,8 @@ class InventoryData(object):
                 g.add_host(h)
                 self._groups_dict_cache = {}
                 display.debug("Added host %s to group %s" % (host, group))
+        else:
+            raise AnsibleError("Invalid empty host name provided: %s" % host)
 
     def remove_host(self, host):