sharing: Allow double quotes in path strings

Unix paths can contain double quotes. Allow entering paths with double quotes by
escaping them in c-style[1] and retrieve them back properly.

1) https://httpd.apache.org/docs/2.4/expr.html

Tests:

Run tests on with various paths:

- /var/a b

- /var/c"d

- /var/ef"

Run the following tests.

- Create a directory with the test path and create a sample file inside it.

- Add a share with the test path.

- Ensure that the share is accessible and the file can be downloaded.

- Ensure that the list of the shares shows the path correctly.

- Ensure that the share can be edited.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>

actions/sharing

@@ -57,7 +57,7 @@ def load_augeas():
 def subcommand_add(arguments):
     """Add a share to Apache configuration."""
     name = arguments.name
-    path = '"' + arguments.path + '"'
+    path = '"' + arguments.path.replace('"', r'\"') + '"'
     groups = arguments.groups
     is_public = arguments.is_public
     url = '/share/' + name
@@ -150,11 +150,13 @@ def _list(aug=None):
         url = aug.get(match + '/arg[1]')
         path = aug.get(match + '/arg[2]')
 
+        path = path.removesuffix('"').removeprefix('"')
+        path = path.replace(r'\"', '"')
         try:
             name = _get_name_from_url(url)
             shares.append({
                 'name': name,
-                'path': path.strip('"'),
+                'path': path,
                 'url': '/share/' + name
             })
         except ValueError:

plinth/modules/sharing/forms.py

@@ -20,9 +20,8 @@ class AddShareForm(forms.Form):
             'A lowercase alpha-numeric string that uniquely identifies a '
             'share. Example: <em>media</em>.'))
 
-    path = forms.RegexField(
-        label=_('Path to share'), strip=True, regex=r'^[^\"]+$',
-        help_text=_(
+    path = forms.CharField(
+        label=_('Path to share'), strip=True, help_text=_(
             'Disk path to a folder on this server that you intend to share.'))
 
     is_public = forms.BooleanField(