MCP editing mode inputs ignore last characters and do not fill under certain conditions

[jack5github]

Describe the bug

When adding or editing an MCP server, it is common to see the error Tools field is required (use "*" for all tools) when attempting to save changes. Entering ** works, but then it becomes apparent that the last character of the MCP server name and command were not saved. Essentially, the last typed characters of all free input fields in MCP editing mode are treated as if they don't exist.

In addition to the above, selecting an MCP server by number (rather than using /mcp edit) causes the edit form to fail to be populated with the chosen MCP server's parameters, requiring everything to be entered from scratch.

Affected version

GitHub Copilot CLI 0.0.400

Steps to reproduce the behavior

1. Open copilot.
2. Execute /mcp add.
3. Fill in the inputs as follows:
   • Server Name: playwright-test
   • Command: npx playwright run-test-mcp-server
   • Tools: *
4. Attempt to save the MCP server with Ctrl+S. The error Tools field is required (use "*" for all tools) will appear.
5. Replace the Tools input value with ** and save the MCP server. The server name will be displayed in the numbered list as playwright-tes.
6. Press the number of the MCP server to edit it. All input boxes will be blank.
7. Exit editing mode and instead execute /mcp edit playwright-tes. All input box values will be incorrect, missing their last characters.

Expected behavior

• Input values should be saved as-is.
• The MCP editing mode should collect the parameters of the server being edited when selecting one by number.

Additional context

• Operating system: Microsoft Windows 11 Pro 10.0.26200 Build 26200
• CPU architecture: x86_64
• Terminal emulator: Windows PowerShell

This bug did not exist in Copilot version 0.0.389 commit 95ae76e.