Refuse to convert a non-empty directory into a link with the file module

Also adds an integration test for the above.

Fixes #7254

library/files/file

@@ -192,8 +192,13 @@ def main():
         if state == 'hard':
             if not os.path.isabs(src):
                 module.fail_json(msg="absolute paths are required")
-
-        elif prev_state in ['file', 'hard', 'directory'] and not force:
+        elif prev_state == 'directory':
+            if not force:
+                module.fail_json(path=path, msg='refusing to convert between %s and %s for %s' % (prev_state, state, src))
+            elif len(os.listdir(path)) > 0:
+                # refuse to replace a directory that has files in it
+                module.fail_json(path=path, msg='the directory %s is not empty, refusing to convert it' % path)
+        elif prev_state in ['file', 'hard'] and not force:
             module.fail_json(path=path, msg='refusing to convert between %s and %s for %s' % (prev_state, state, src))
 
         if prev_state == 'absent':

test/integration/roles/test_file/tasks/main.yml

@@ -183,5 +183,48 @@
     that:
       - "file13_result.changed == true"
 
-- name: remote directory foobar
+- name: remove directory foobar
   file: path={{output_dir}}/foobar state=absent
+  register: file14_result
+
+- name: verify that the directory was removed
+  assert:
+    that:
+      - 'file14_result.changed == true'
+      - 'file14_result.state == "absent"'
+
+- name: create a test sub-directory
+  file: dest={{output_dir}}/sub1 state=directory
+  register: file15_result
+
+- name: verify that the new directory was created
+  assert:
+    that:
+      - 'file15_result.changed == true'
+      - 'file15_result.state == "directory"'
+
+- name: create test files in the sub-directory
+  file: dest={{output_dir}}/sub1/{{item}} state=touch
+  with_items:
+  - file1
+  - file2
+  - file3
+  register: file16_result
+
+- name: verify the files were created
+  assert:
+    that:
+      - 'item.changed == true'
+      - 'item.state == "file"'
+  with_items: file16_result.results
+
+- name: try to force the sub-directory to a link
+  file: src={{output_dir}}/testing dest={{output_dir}}/sub1 state=link force=yes
+  register: file17_result
+  ignore_errors: true
+
+- name: verify the directory was not replaced with a link
+  assert:
+    that:
+      - 'file17_result.failed == true'
+      - 'file17_result.state == "directory"'