bug#23074: 25.1.50; X11: `use-fancy-splash-screens-p` erroneously returns nil.

[Eli Zaretskii <eliz@gnu.org>]

> Date:  Mon, 21 Mar 2016 18:03:21 -0700
> From:  Keith David Bershatsky <esq@lawlist.com>
> Cc:  23074@debbugs.gnu.org
> 
> The following test was performed with no toolkit -- i.e., --with-x 
> --with-x-toolkit=no --with-ns=no
> 
> M-: (frame-height) RET
> 
>   Evaluating the above gives me a value of 35.
> 
> M-: (image-size (create-image (fancy-splash-image-file))) RET
> 
>   Evaluating the above gives me a value of:  (41.625 . 15.533333333333333)
> 
> The value for `fancy-splash-image-file` is:  "splash.svg"

Then, with the code you modified in startup.el, you do succeed to get
the fancy splash image, but the text below it is only partially
visible, right?  IOW, one or two (maybe even 3) last lines are not
visible?  This is exactly what the test was trying to avoid.  So if we
go with your proposal, it is not clear why we should insist on some
minimal frame height at all.

(Or maybe you don't have auto-save file lists in your home directory,
in which case your startup screen shows 2 lines less than it does on
my system, and you are not aware of the problem for that reason.)

I think the correct solution will be to increase the default frame
size by 1 or maybe even 2 lines.  Because on my system, the last line
is only partially visible, so the calculation in
use-fancy-splash-screens-p is slightly inaccurate (because it is
off-by-one -- we need to subtract 2 from the frame height, not 1).