Recursively create the remote safe directory

Previously if the remote safe directory wasn't fully created, the script
would crash and leave files in the remote processing directory

dangerzone-webdav-processor

@@ -357,6 +357,18 @@ def main():
 
 
 class ProcessingClient(wc.Client):
+    def mkdir_recursive(self, path: str):
+        """Loop through the parts of a path, and create them all"""
+        # build and create each subdirectory one path component at a time
+        full_path: str = ""
+        for component in path.split("/"):
+            full_path = join(full_path, component)
+            if not self.mkdir(full_path):
+                # couldn't create the directory, return an error
+                return False
+
+        return True
+
     def process_path(self, folder, path):
         if is_special_folder(path):
             logging.debug("found special folder %s, skipping", path)
@@ -442,8 +454,12 @@ class ProcessingClient(wc.Client):
 
                 # 6. on success, upload the sanitized file to a safe/
                 #    folder, move the original to dangerzone/processed
-                remote_safe_path = join(folder, "safe", path)
+                remote_safe_directory = join(folder, "safe")
+                remote_safe_path = join(remote_safe_directory, path)
                 local_safe_path = join(self.sanitizer.safe_dir, path)
+                logging.info(f"recursively creating remote safe directory {remote_safe_directory}")
+                if not self.dryrun:
+                    self.mkdir_recursive(remote_safe_directory)
                 logging.info(
                     "uploading %s to %s", local_safe_path, remote_safe_path
                 )