bug#19322: 25.0.50; 1.6Mb one line file chocks Emacs

[Vitalie Spinu <spinuvit@gmail.com>]

Hi,

When I am trying to open this 1.6M file:

  http://vitalie.spinu.info/tmp/tmp.data

`emacs -q` locks and the only way to get out is a sigterm. I can open it
with older emacses:

  Emacs 24.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.10.9),  and
  Emacs 24.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.10.9)


Thanks,

   Vitalie


----

In GNU Emacs 25.0.50.1 (x86_64-pc-linux-gnu, GTK+ Version 3.12.2)
 of 2014-11-17 on lgw01-08
Windowing system distributor `The X.Org Foundation', version 11.0.11600000
System Description:	Ubuntu 14.10

Configured using:
 `configure --build=x86_64-linux-gnu --prefix=/usr
 '--includedir=${prefix}/include' '--mandir=${prefix}/share/man'
 '--infodir=${prefix}/share/info' --sysconfdir=/etc --localstatedir=/var
 '--libdir=${prefix}/lib/x86_64-linux-gnu'
 '--libexecdir=${prefix}/lib/x86_64-linux-gnu' --disable-maintainer-mode
 --disable-dependency-tracking --prefix=/usr --sharedstatedir=/var/lib
 --program-suffix=-snapshot --with-x=yes --with-x-toolkit=gtk3
 'CFLAGS=-g -O2 -fstack-protector-strong -Wformat
 -Werror=format-security' CPPFLAGS=-D_FORTIFY_SOURCE=2
 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro''

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix