bug#31341: 26.1; setting ispell-base-dicts-override-alist no longer working

[Anders Johansson <mejlaandersj@gmail.com>]

After updating to the 26.1 release candidate the custom 
dictionaries I have added via ispell-base-dicts-override-alist are 
no longer added.


I believe that this bug is due to ispell.el being compiled with 
lexical-binding since 26.1, which means that the value of 
ispell-base-dicts-override-alist set via 
ispell-initialize-spellchecker-hook will no longer be in scope in 
the body of ispell-set-spellchecker-params.
(This is the recommended usage in the docstring of 
ispell-initialize-spellchecker-hook).

I guess some other mechanism would have to be devised when using 
lexical-binding.



In GNU Emacs 26.1 (build 3, x86_64-pc-linux-gnu, GTK+ Version 
3.22.30)
 of 2018-04-29 built on ajjb
Windowing system distributor 'The X.Org Foundation', version 
11.0.11906000
Recent messages:

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib 
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft 
 --with-modules 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe 
 -fstack-protector-strong -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2 
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'
Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS 
NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB 
TOOLKIT_SCROLL_BARS GTK3 X11 MODULES THREADS LIBSYSTEMD LCMS2
Important settings:
  value of $LC_MONETARY: sv_SE.UTF-8
  value of $LC_NUMERIC: sv_SE.UTF-8
  value of $LC_TIME: sv_SE.UTF-8
  value of $LANG: sv_SE.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix