register: fail when invalid var name is specified (#56456)

lib/ansible/executor/task_executor.py

@@ -30,7 +30,7 @@ from ansible.utils.listify import listify_lookup_plugin_terms
 from ansible.utils.unsafe_proxy import UnsafeProxy, wrap_var
 from ansible.vars.clean import namespace_facts, clean_facts
 from ansible.utils.display import Display
-from ansible.utils.vars import combine_vars
+from ansible.utils.vars import combine_vars, isidentifier
 
 display = Display()
 
@@ -647,6 +647,9 @@ class TaskExecutor:
             # update the local copy of vars with the registered value, if specified,
             # or any facts which may have been generated by the module execution
             if self._task.register:
+                if not isidentifier(self._task.register):
+                    raise AnsibleError("Invalid variable name in 'register' specified: '%s'" % self._task.register)
+
                 vars_copy[self._task.register] = wrap_var(result)
 
             if self._task.async_val > 0:

test/integration/targets/templating_settings/runme.sh

@@ -3,5 +3,4 @@
 set -eux
 
 ansible-playbook test_templating_settings.yml -i ../../inventory -v "$@"
-ansible-playbook warn_on_register.yml -i ../../inventory -v "$@" 2>&1| grep 'is not templatable, but we found'
 [ "$(ansible-playbook dont_warn_register.yml -i ../../inventory -v "$@" 2>&1| grep -c 'is not templatable, but we found')" == "0" ]

test/integration/targets/templating_settings/warn_on_register.yml

@@ -1,8 +0,0 @@
-- hosts: testhost
-  gather_facts: false
-  vars:
-    thisshouldwarn: noreally
-  tasks:
-    - name: template in register warns
-      debug: msg=unimportant
-      register: '{{ thisshouldwarn }}'

test/integration/targets/uri/tasks/main.yml

@@ -56,7 +56,7 @@
 
 - name: fetch pass_json
   uri: return_content=yes url=http://localhost:{{ http_port }}/{{ item }}.json
-  register: pass
+  register: fetch_pass_json
   with_sequence: start=0 end=4 format=pass%d
 
 - name: check pass_json
@@ -66,7 +66,7 @@
       - item.0.stat.checksum == item.1.content | checksum
   with_together:
     - "{{pass_checksum.results}}"
-    - "{{pass.results}}"
+    - "{{fetch_pass_json.results}}"
 
 
 - name: checksum fail_json