copy: Use the local file's mode for the argument if not explicitly given. (#17780)

* Use the local file's mode to for the argument if not explicitly given.

Fixes https://github.com/ansible/ansible-modules-core/issues/1124

* Fix octal mode for py3

* Implement preserve instead of null

* Remove duplicate line

* Update comment

* Use stat module per toshia's suggestion

lib/ansible/plugins/action/copy.py

@@ -21,6 +21,7 @@ __metaclass__ = type
 
 import json
 import os
+import stat
 import tempfile
 
 from ansible.errors import AnsibleError
@@ -147,6 +148,9 @@ class ActionModule(ActionBase):
         # expand any user home dir specifier
         dest = self._remote_expand_user(dest)
 
+        # Keep original value for mode parameter
+        mode_value = self._task.args.get('mode', None)
+
         diffs = []
         for source_full, source_rel in source_files:
 
@@ -155,6 +159,12 @@ class ActionModule(ActionBase):
             # Generate a hash of the local file.
             local_checksum = checksum(source_full)
 
+            # Get the local mode and set if user wanted it preserved
+            # https://github.com/ansible/ansible-modules-core/issues/1124
+            if self._task.args.get('mode', None) == 'preserve':
+                lmode = '0%03o' % stat.S_IMODE(os.stat(source_full).st_mode)
+                self._task.args['mode'] = lmode
+
             # If local_checksum is not defined we can't find the file so we should fail out.
             if local_checksum is None:
                 result['failed'] = True
@@ -295,6 +305,9 @@ class ActionModule(ActionBase):
             if 'path' in module_return and 'dest' not in module_return:
                 module_return['dest'] = module_return['path']
 
+            # reset the mode
+            self._task.args['mode'] = mode_value
+
         # Delete tmp path if we were recursive or if we did not execute a module.
         if not delete_remote_tmp or (delete_remote_tmp and not module_executed):
             self._remove_tmp_path(tmp)