Attempting to eval an invalid expansion in a subshell (e.g. by doing a
feature test for bash-style ${x/y/z} expansions) in a script sourced
with 'command .' causes program flow corruption in dash, current git as
well as 0.5.10.2.
Test scripts, one sourcing the other with 'command .':
# test.sh
echo one
command . ./test2.sh
echo four
# test2.sh
echo two
(eval 'y=${x/y/z}')
echo three
Initial output:
$ dash test.sh
one
two
test.sh: 1: eval: Bad substitution
four
Then dash goes in some kind of half-interactive mode. It accepts
commands like 'ls' but does not display a prompt. The 'set -i' command
activates the prompt.
When leaving that phantom interactive shell with 'exit' or ^D, the final
output is:
three
four
Note that the 'echo four' in test.sh is executed twice.
Also, gwsh does not exhibit these symptoms.
- Martijn
