Symfony based autocomplete breaks SCP autocomplete - bash

Question

I am using the PHP tools http://robo.li and n98-magerun.phar - both are based on Sympfony's CLI components.
When I use such a autocomplete script:
https://gist.github.com/caseyfw/51bdbcb37e5dfb91b74e
#!/bin/sh
function __robo_list_cmds ()
{
robo list --raw | awk '{print $1}' | sort
}
function __robo_list_opts ()
{
robo list --no-ansi | sed -e '1,/Options:/d' -e '/^$/,$d' -e 's/^ *//' -e 's/ .*//' | sort
}
_robo()
{
local cur="${COMP_WORDS[COMP_CWORD]}"
COMPREPLY=($(compgen -W "$(__robo_list_opts) $(__robo_list_cmds)" -- ${cur}))
return 0;
}
complete -o default -F _robo robo
COMP_WORDBREAKS=${COMP_WORDBREAKS//:}
It breaks the autocomplete of the scp command (which usually completes files on a remote server - but with this - unrelated - robo completion in place, scp removes the host name from the command)
Why is that? How to fix?
EDIT
based on the answer, the fixed version is here:
https://gist.github.com/amenk/d68f1fe54b156952ced621f771ff48ba

Answer 1

This has probably nothing to do with your robo compspec. Nor with the _scp completion function associated with scp.
It is probably due to your COMP_WORDBREAKS=${COMP_WORDBREAKS//:}.
You removed : from the list of separators. Apparently _scp is robust enough to behave the same with or without : as a word separator. It returns the same list of candidate completions. But the token that gets substituted when _scp returns only one candidate for the completion of, e.g. scp host:public_ht, is host:public_ht, instead of just public_ht. Proof:
$ _foobar () { COMPREPLY=bazcux; return 0; }
$ complete -o default -F _foobar foobar
$ echo $COMP_WORDBREAKS
"'><=;|&(:
If you try to complete foobar host:public_ht, you get foobar host:bazcux because the substituted token is just public_ht. While with:
$ COMP_WORDBREAKS=${COMP_WORDBREAKS//:}
$ echo $COMP_WORDBREAKS
"'><=;|&(
if you try to complete foobar host:public_ht, you get foobar bazcux because it is the complete host:public_ht that is replaced by bazcux.
The solution to your problem is probably to adapt your _robo completion function such that it does not require that : is not a word separator. Something like:
_stem () {
local lcur lprev
lcur="$cur"
stem="$lcur"
for (( i = cword - 1; i >= 0; i -= 1 )); do
lprev="${words[i]}"
[[ $lcur == ":" ]] && [[ $lprev == ":" ]] && break
[[ $lcur != ":" ]] && [[ $lprev != ":" ]] && break
stem="$lprev$stem"
lcur="$lprev"
done
}
_robo () {
local cur prev words cword
_init_completion || return
local stem options
options=($(__robo_list_opts) $(__robo_list_cmds))
COMPREPLY=()
_stem
COMPREPLY=($(compgen -W '${options[#]}' -- "$stem"))
[[ $stem =~ : ]] && stem=${stem%:*}: && COMPREPLY=(${COMPREPLY[#]#"$stem"})
return 0
}
complete -o default -F _robo robo
A much (apparently) simpler solution consists in replacing the _stem function above by the existing __reassemble_comp_words_by_ref function of the bash_completion library:
_robo () {
local cur prev words cword
_init_completion || return
__reassemble_comp_words_by_ref ":" words cword
options=($(__robo_list_opts) $(__robo_list_cmds))
COMPREPLY=($(compgen -W '${options[#]}' -- "$cur"))
return 0
}
complete -o default -F _robo robo
All this is probably not exactly what you want. I do not know robo.il and there are probably many improvements that would take more context into account to propose specific completions. But it may be a starting point.