Troublesome checkwinsize (none) behaviour

[werner]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc -I/home/abuild/rpmbuild/BUILD/bash-4.2 
-L/home/abuild/rpmbuild/BUILD/bash-4.2/../readline-6.2
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-suse-linux-gnu' 
-DCONF_VENDOR='suse' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -fmessage-length=0 -O2 -Wall 
-D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables 
-fasynchronous-unwind-tables -g  -D_GNU_SOURCE -DRECYCLES_PIDS -Wall -g 
-std=gnu89 -Wuninitialized -Wextra -Wno-unprototyped-calls -Wno-switch-enum 
-Wno-unused-variable -Wno-unused-parameter -ftree-loop-linear -pipe 
-fprofile-use
uname output: Linux d88 3.7.10-1.11-desktop #1 SMP PREEMPT Thu May 16 20:27:27 
UTC 2013 (adf31bb) x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-suse-linux-gnu

Bash Version: 4.2
Patch Level: 42
Release Status: release

Description:
        As subject says:
          * If checkwinsize is _not_ set the bash does not update the
            internal LINES and COLUMNS varaible during a command/job is
            running in foreground on same terminal.
          * If checkwinsize is set bash/libreadline does export LINES and
            COLUMNS breaking ncurses/TIOCGWINSZ based commands/jobs.
        both cause bug reports here. That is if I override the default and
        set the check_window_size to 1 in jobs.c I'll beaten by bug reports
        and upstream (compare e.g. with
        https://bugzilla.novell.com/show_bug.cgi?id=793536).
        If I do not change the upstream behaviour I'll also beaten by bug
        reports because know bash does not know about size changes during
        an other job is in foreground
        (compare e.g. with https://bugzilla.novell.com/show_bug.cgi?id=828877)
Fix:
        The bash/libreadline may (IMHO) update LINES and COLUMNS after a job
        without exporting LINES and COLUMNS.  Simply to have a correct command
        line behaviour of the bash its self after jobs had finished as well
        as for the jobs them self to not to depend on static LINES and COLUMNS
        but on TIOCGWINSZ only.