Set accept_hostkey to False by default in the git module and fail

early if the key is unknown

source_control/git

@@ -45,7 +45,7 @@ options:
               branch name, or a tag name.
     accept_hostkey:
         required: false
-        default: true
+        default: false
         version_added: "1.5"
         description:
             - Add the hostkey for the repo url if not already added.
@@ -359,7 +359,7 @@ def main():
             force=dict(default='yes', type='bool'),
             depth=dict(default=None, type='int'),
             update=dict(default='yes', type='bool'),
-            accept_hostkey=dict(default='yes', type='bool'),
+            accept_hostkey=dict(default='no', type='bool'),
             executable=dict(default=None),
             bare=dict(default='no', type='bool'),
         ),
@@ -378,8 +378,8 @@ def main():
     git_path  = module.params['executable'] or module.get_bin_path('git', True)
 
     # add the git repo's hostkey 
-    if module.params['accept_hostkey']:
+    #if module.params['accept_hostkey']:
-        add_git_host_key(module, repo, accept_hostkey=True)
+    add_git_host_key(module, repo, accept_hostkey=module.params['accept_hostkey'])
 
     if bare:
         gitconfig = os.path.join(dest, 'config')