bug#23935: 25.1.50; simple reproducible crash for emacs -Q: `M-: (+ 1997 120 400)'

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 10 Jul 2016 11:19:01 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 23935@debbugs.gnu.org
> 
>     Shonar Bangla (TrueType)    REG_SZ    Shonar.ttf
>     Shonar Bangla Bold (TrueType)    REG_SZ    Shonarb.ttf
> 
> I see no other matches between those two lists.

Hmm... these are stock Windows fonts, so unlikely to cause the crash.

I guess we will have to detect the problematic line(s) in HELLO one by
one.  Please start "emacs -Q", then type "C-x 2", and shrink the upper
window to just 5 lines.  Then type "C-h H" in that window -- this
shouldn't crash, as the first 5 lines of HELLO are pure ASCII.

Now click on the bottom arrow of the scroll bar of that window one
click at a time.  Each click should show one more line.  (Some clicks
might take a couple of seconds to react, as Emacs searches for the
fonts it needs.)  When the problematic line is about to enter the
view, the click to scroll that line into the window will crash Emacs.
Please tell what was the last line you were able to display before the
crash.