Annoying resizing of Rmail windows

[Eli Zaretskii]

With yesterday's trunk, I see an annoying resizing of windows when I
work in Rmail.  (I didn't try to use Rmail with Emacs 24 for a long
time.)

My window configuration in an Rmail frame is to split the frame in 2,
and have the Rmail summary window above the window where Rmail shows
the current message.  I normally make the summary window small, so
that only a few lines are shown in it, with the rest of the frame
taken by the message display.

I have even-window-heights set to nil in my ~/.emacs.  I expect that,
once I determine the size of each of these two windows, they are never
resized by Emacs, only by myself.

This workd in Emacs 23.3, but doesn't work with 24.0.50: whenever
Rmail displays another message (e.g., when I type `n' or `p' to go to
the next or previous message), the window sizes are "evened", although
even-window-heights is nil.

Stepping with Edebug through the Rmail code reveals that the windows
are resized by the function rmail-pop-to-buffer, which calls
pop-to-buffer.

I see that the value of display-buffer-alist has this:

  (reuse-window-even-sizes . t)

Shouldn't that part be gone when even-window-heights is nil?

In any case, please help me get rid of this annoyance, TIA.