Why I cannot quit the window using `quit-window`?

Question

Say I have two existing files named "file1.el" and "file2.el".

Then I perform the following steps:

1. I open a file named "file1.el"

2. C-x C-f a file named "file2.el", now currently I have 1 window and it displays the "file2.el" buffer.

3. I use eval-expression an expression (display-buffer "file1.el"), it opens a new window that displays file1.el buffer on the same frame.

4. I want to kill the file1.el buffer and its corresponding window, so I eval-expression an expression (quit-window t (get-buffer-window "file1.el")), and I got what I want.

However, things are different when I do some buffer switches on the window displaying "file1.el", just after step 3. If I have done it, the step 4 will only kill the "file1.el" buffer, but NOT quitting the window that displaying it. Instead, after step 4, that window will display another buffer that I've switch to previously.

My question is that why quit-window behavior is different in this scenario?

Answer 1

Thanks @NickD for the hint. The reason why quit-window does not quit the window is that, each window itself maintains a history of the buffers it has displayed. And the implementation of quit-restore-window makes use of it, from "(elisp) Quitting Windows":

If prev-buffer is still live when quitting window, quitting the window may reuse window to display prev-buffer