minor fixes to template function

- make sure it calls itself correctly, now passes same params as it recieves
- vars is reserved, changed for templatevars to avoid confustion
- forcing mustaches again since the removal broke 'listification' as per #9622
- fixes incorrectly successful tests using undefined var, now it is defined
- now returns empty list if items is None to avoid errors

lib/ansible/runner/__init__.py

@@ -723,18 +723,21 @@ class Runner(object):
             # strip out any jinja2 template syntax within
             # the data returned by the lookup plugin
             items = utils._clean_data_struct(items, from_remote=True)
-            if type(items) != list:
-                raise errors.AnsibleError("lookup plugins have to return a list: %r" % items)
-
-            if len(items) and utils.is_list_of_strings(items) and self.module_name in [ 'apt', 'yum', 'pkgng', 'zypper' ]:
-                # hack for apt, yum, and pkgng so that with_items maps back into a single module call
-                use_these_items = []
-                for x in items:
-                    inject['item'] = x
-                    if not self.conditional or utils.check_conditional(self.conditional, self.basedir, inject, fail_on_undefined=self.error_on_undefined_vars):
-                        use_these_items.append(x)
-                inject['item'] = ",".join(use_these_items)
-                items = None
+            if items is None:
+                items = []
+            else:
+                if type(items) != list:
+                    raise errors.AnsibleError("lookup plugins have to return a list: %r" % items)
+
+                if len(items) and utils.is_list_of_strings(items) and self.module_name in [ 'apt', 'yum', 'pkgng', 'zypper' ]:
+                    # hack for apt, yum, and pkgng so that with_items maps back into a single module call
+                    use_these_items = []
+                    for x in items:
+                        inject['item'] = x
+                        if not self.conditional or utils.check_conditional(self.conditional, self.basedir, inject, fail_on_undefined=self.error_on_undefined_vars):
+                            use_these_items.append(x)
+                    inject['item'] = ",".join(use_these_items)
+                    items = None
 
         def _safe_template_complex_args(args, inject):
             # Ensure the complex args here are a dictionary, but

lib/ansible/utils/__init__.py

@@ -1469,7 +1469,7 @@ def listify_lookup_plugin_terms(terms, basedir, inject):
             # if not already a list, get ready to evaluate with Jinja2
             # not sure why the "/" is in above code :)
             try:
-                new_terms = template.template(basedir, terms, inject, convert_bare=True, fail_on_undefined=C.DEFAULT_UNDEFINED_VAR_BEHAVIOR)
+                new_terms = template.template(basedir, "{{%s}}" % terms, inject, convert_bare=True, fail_on_undefined=C.DEFAULT_UNDEFINED_VAR_BEHAVIOR)
                 if isinstance(new_terms, basestring) and "{{" in new_terms:
                     pass
                 else:

lib/ansible/utils/template.py

@@ -100,33 +100,33 @@ def lookup(name, *args, **kwargs):
     else:
         raise errors.AnsibleError("lookup plugin (%s) not found" % name)
 
-def template(basedir, varname, vars, lookup_fatal=True, depth=0, expand_lists=True, convert_bare=False, fail_on_undefined=False, filter_fatal=True):
+def template(basedir, varname, templatevars, lookup_fatal=True, depth=0, expand_lists=True, convert_bare=False, fail_on_undefined=False, filter_fatal=True):
     ''' templates a data structure by traversing it and substituting for other data structures '''
     from ansible import utils
 
     try:
         if convert_bare and isinstance(varname, basestring):
             first_part = varname.split(".")[0].split("[")[0]
-            if first_part in vars and '{{' not in varname and '$' not in varname:
+            if first_part in templatevars and '{{' not in varname and '$' not in varname:
                 varname = "{{%s}}" % varname
-    
+
         if isinstance(varname, basestring):
             if '{{' in varname or '{%' in varname:
-                varname = template_from_string(basedir, varname, vars, fail_on_undefined)
+                varname = template_from_string(basedir, varname, templatevars, fail_on_undefined)
 
                 if (varname.startswith("{") and not varname.startswith("{{")) or varname.startswith("["):
-                    eval_results = utils.safe_eval(varname, locals=vars, include_exceptions=True)
+                    eval_results = utils.safe_eval(varname, locals=templatevars, include_exceptions=True)
                     if eval_results[1] is None:
                         varname = eval_results[0]
 
             return varname
-    
+
         elif isinstance(varname, (list, tuple)):
-            return [template(basedir, v, vars, lookup_fatal, depth, expand_lists, fail_on_undefined=fail_on_undefined) for v in varname]
+            return [template(basedir, v, templatevars, lookup_fatal, depth, expand_lists, convert_bare, fail_on_undefined, filter_fatal) for v in varname]
         elif isinstance(varname, dict):
             d = {}
             for (k, v) in varname.iteritems():
-                d[k] = template(basedir, v, vars, lookup_fatal, depth, expand_lists, fail_on_undefined=fail_on_undefined)
+                d[k] = template(basedir, v, templatevars, lookup_fatal, depth, expand_lists, convert_bare, fail_on_undefined, filter_fatal)
             return d
         else:
             return varname

test/units/TestUtils.py

@@ -568,10 +568,8 @@ class TestUtils(unittest.TestCase):
         basedir = os.path.dirname(__file__)
 
         # Straight lookups
-        self.assertEqual(ansible.utils.listify_lookup_plugin_terms('things', basedir, dict()),
-                         ['things'])
-        self.assertEqual(ansible.utils.listify_lookup_plugin_terms('things', basedir, dict(things=['one', 'two'])),
-                         ['one', 'two'])
+        self.assertEqual(ansible.utils.listify_lookup_plugin_terms('things', basedir, dict(things=[])), [])
+        self.assertEqual(ansible.utils.listify_lookup_plugin_terms('things', basedir, dict(things=['one', 'two'])), ['one', 'two'])
 
         # Variable interpolation
         self.assertEqual(ansible.utils.listify_lookup_plugin_terms('things', basedir, dict(things=['{{ foo }}', '{{ bar }}'], foo="hello", bar="world")),