This bug occurs on `shell_insert_output` and `shell_append_output` commands. The previous implementation would create a child process using the Rust stdlib's `Command` builder. However, when nothing should be piped in from the editor, the default value for `stdin` would be used. According to the Rust stdlib documentation that is `Stdio::inherit` which will make the child process inherit the parent process' stdin. This would cause the terminal to freeze. This change will set the child process' stdin to `Stdio::null` whenever it doesn't pipe it. In the `if` statement where this change was made there was an extra condition for windows that I am not sure if would require some special treatment.