Turn off FreeRDP's file clipboard (copying a file froze the session)

README.md

@@ -54,7 +54,7 @@ flowchart TD
         end
 
         subgraph FreeRDPClient["FreeRDP 3 (xfreerdp)"]
-            RDPProcess["xfreerdp /v:host /sound /clipboard /drive:SharedFolder,/shared"]
+            RDPProcess["xfreerdp /v:host /sound /clipboard:files-to:off /drive:SharedFolder,/shared"]
         end
     end
 
@@ -258,6 +258,8 @@ Over plain HTTP (port 8080) a paste still sends the image, but the keystroke can
 
 Images reach Windows as bitmaps: Ubuntu's FreeRDP build can't convert PNG itself, so the gateway adds a BMP copy of every pasted image. Transparent areas become white.
 
+Files can't be copied through the clipboard: a browser has no way to put a file on your local clipboard, so FreeRDP's file clipboard is turned off. Move files through the shared folder instead (`\\tsclient\SharedFolder` in Windows, **Shared Files** in the WebUI; see [How File Sharing Works](#how-file-sharing-works)).
+
 ---
 
 ## Windows Machine Setup

root/app/backend/session_manager.py

@@ -177,7 +177,10 @@ def _build_rdp(self, config: Dict[str, Any]) -> Launch:
 
         # Bidirectional Clipboard Synchronization
         if config.get("enable_clipboard", True):
-            args.append("+clipboard")
+            # Text and images only. FreeRDP can hand copied files to Linux apps only
+            # through a FUSE mount, and the container has no /dev/fuse; with files on,
+            # copying a file in Windows Explorer froze the session.
+            args.append("/clipboard:files-to:off")
             if clipboard_debug_enabled():
                 args.append(f"/log-filters:{CLIPBOARD_LOG_FILTERS}")
 

tests/test_session_manager.py

@@ -58,11 +58,18 @@ def test_rdp_target_and_optional_flags(mgr):
     args = launch.stdin_text
     assert "/v:pc.local:3390" in args
     assert "/sound" not in args
-    assert "+clipboard" not in args
+    assert "clipboard" not in args
     assert "/drive" not in args
     assert "/cert:ignore" not in args
 
 
+def test_rdp_clipboard_leaves_files_out(mgr):
+    """Copied files need a FUSE mount the container lacks; offering them froze the session."""
+    args = mgr._build_rdp({"host": "pc.local", "port": 3389}).stdin_text.splitlines()
+    assert "/clipboard:files-to:off" in args
+    assert "+clipboard" not in args
+
+
 def test_rdp_resolution_modes(mgr):
     dynamic = mgr._build_rdp({"host": "h", "port": 1, "resolution": "dynamic"})
     assert "/dynamic-resolution" in dynamic.stdin_text