first_found fix no terms option (#76550) (#81451)

For backport without the fix for multiple items clobbering previous settings

Co-authored-by: Sloane Hertel <19572925+s-hertel@users.noreply.github.com>

changelogs/fragments/first_found_fixes.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - first found lookup has been updated to use the normalized argument parsing (pythonic) matching the documented examples.

lib/ansible/plugins/lookup/first_found.py

@@ -165,6 +165,9 @@ class LookupModule(LookupBase):
         total_search = []
         skip = False
 
+        if not terms and kwargs:
+            terms = ['']
+
         # can use a dict instead of list item to pass inline config
         for term in terms:
             if isinstance(term, Mapping):

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

@@ -94,3 +94,11 @@
 - assert:
     that:
       - foo is defined
+
+# TODO: no 'terms' test
+- name: test first_found lookup with no terms
+  set_fact:
+    no_terms: "{{ query('first_found', files=['missing1', 'hosts', 'missing2'], paths=['/etc'], errors='ignore') }}"
+
+- assert:
+    that: "no_terms|first == '/etc/hosts'"