Re: tab completion error

[Chet Ramey]

On 9/25/23 5:40 PM, Mike Jonkmans wrote:
> On Mon, Sep 25, 2023 at 03:44:15PM -0400, Chet Ramey wrote:
> > On 9/25/23 12:16 PM, Mike Jonkmans wrote:
> > > On Mon, Sep 25, 2023 at 11:11:04AM -0400, Brian Vargo wrote:
> > > > This is going to be very hard to explain over email.  I tried to use script
> > > > from util-linux in GNU bash v.5.1.16 on Ubuntu 22.04, but that doesn't seem
> > > > to offer any help.
> > >
> > > A smaller reproducer:
> > >
> > > mkdir empty
> > > cd empty
> > > mkdir a\ b
> > > touch a\ b/f\ 1
> > > touch a\ b/f\ 2
> > >
> > > ls "a b"/"f<TAB>
> >
> > OK. I still can't reproduce it, but it may be due to the fact that readline
> > completes unclosed quoted strings as individual words. This means that the
> > word actually being completed in the above case there is "f", not "a b/f".
>
> If I manually add the missing quote at the end (before <TAB>),
> then completion works correctly.
>
> So perhaps the completion code could detect an unclosed quote
> and then add one at the end, before doing the completion?

That would disable readline's ability to complete on unclosed quoted
strings, which has been a feature since the beginning. There would have
to be a much more compelling reason than this to break compatibility
like that.

> > The default bash completion doesn't give produce any completions for this,
> > which implies that this is actually the work of bash-completion.
>
> That is right.
>
> Now without bash-completion (Ubuntu 22.04; bash 5.1):
> ls a\ b/"<TAB>
> Gives:
> ls a\ b/"a b"/
>
> Is also a (minor) issue.

I'm going to assume that you only have one thing in that directory -- a
directory named `a b'. As such, that's the only possible completion for
the empty string, and that's what bash and readline use for the
replacement.


> > And that might be why. bash-completion takes the word it thinks is being
> > completed ("a b/f"), not the one readline is telling it is being completed
> > ("f") and does the right thing with it. Unfortunately, since the word being
> > completed is "f", that's what gets replaced with the new completion text.
> >
> > It's sometimes easier to not put in the quotes yourself and let readline
> > completion quoting add them.
>
> That's how users should work around it.
>
> Do we need to file an issue with bash-completion?

You might. There are times -- and this is one -- when the word being
completed (passed to the completion function as $2) and the word the
completion function thinks should be used (${COMP_WORDS[$COMP_CWORD]})
are not the same.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/