Hello, Instead of segfaulting, BASH should ensure READELINE_LINE is unset or set and empty.
*Configuration Information:* Machine: x86_64 OS: linux-gnu Compiler: x86_64-pc-linux-gnu-gcc Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I./include -I. -I./include -I./lib -DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/lo +cal/bin:/usr/sbin:/usr/bin:/sbin:/bin' -DSTANDARD_UTILS_PATH='/bin:/usr/bin:/sbin:/usr/sbin' -DSYS_BASHRC='/etc/bash/bashrc' -DSYS_BASH_LOGOUT='/etc/bash/bash_logout' -DNON_INTERACTIVE_LOGIN_SHELLS -DSSH_SOURCE_BASHRC -march=core-avx2 -O3 -pipe -fomit-frame-pointer -mabm -floop-interchange -ftree-loop-di +stribution -floop-strip-mine -floop-block -flto=16 -fuse-linker-plugin -fopenmp -fno-lto -fno-use-linker-plugin -Wno-parentheses -Wno-format-security uname output: Linux client 4.10.8-gentoo #1 SMP Fri Mar 31 19:12:26 CDT 2017 x86_64 Intel(R) Core(TM) i7-5960X CPU @ 3.00GHz GenuineIntel GNU/Linux Machine Type: x86_64-pc-linux-gnu Bash Version: 4.4 Patch Level: 12 Release Status: release *Description:* Unsetting READLINE_LINE in a 'bind -x' causes segmentation fault. *Repeat-By:* # New shell bash --norc --noprofile # Can be done any emacs or vi mode bind -x '"\C-m": unset -v READLINE_LINE' # User hits ctrl+m Segmentation Fault