fix http directory listing

xpra/net/http/directory_listing.py

@@ -3,7 +3,7 @@
 # Xpra is released under the terms of the GNU GPL v2, or, at your option, any
 # later version. See the file COPYING for details.
 
-# duplicated form SimpleHTTPRequestHandler
+# duplicated from SimpleHTTPRequestHandler
 # so that we can re-use it from the quic handler
 # and also so that we can customize it more easily
 
@@ -52,8 +52,9 @@ def list_directory(path:str):
     encoded = '\n'.join(r).encode(enc, 'surrogateescape')
     f = BytesIO()
     f.write(encoded)
-    f.seek(0)
+    contents = f.getvalue()
+    f.close()
     return 200, {
-        "Content-type", f"text/html; charset={enc}",
-        "Content-Length", str(len(encoded)),
-        }, f
+        "Content-type": f"text/html; charset={enc}",
+        "Content-Length": str(len(encoded)),
+    }, contents

xpra/net/http/http_handler.py

@@ -402,8 +402,11 @@ def send_head(self):
                 if not self.directory_listing:
                     self.send_error(403, "Directory listing forbidden")
                     return None
-                return list_directory(path).read()
-
+            code, headers, body = list_directory(path)
+                self.send_response(code)
+                self.extra_headers.update(headers)
+                self.end_headers()
+                return body
         try:
             code, extra_headers, content = load_path(self.headers, path)
             lm = extra_headers.get("Last-Modified")