"chsh -s path/to/shell" argument handling differs from regular chsh

[drjaska]

https://github.com/termux/termux-tools/blob/master/scripts/chsh.in#L16

Line 16 NEW_SHELL=@TERMUX_PREFIX@/bin/$1

This assumes that a full path is not given and expects a binary name from the $PREFIX/bin directory.

Or if abused a relative path starting from that directory but I would assume that to break later on.

I would recommend to check if $1 contains slashes or not.

I would expect chsh -s "$(command -v bash)" to work as it does on other systems but here it results in the shell executable file path /data/data/com.termux/files/usr/bin//data/data/com.termux/files/usr/bin/bash which errors the executability check.