Fix handling of paths with special characters / wildcards

[karlch]

Escapes the characters []?* properly when expanding wildcards such as % and %m.

fixes #553

@pglira @TeaWhyDee @jcjgraf could one of you give this a quick check?

In addition, I was not able to find out what the issue with image.jpg~ should be, all playing around I did with tilde worked just fine. Could someone elaborate, so I can potentially add this to the PR?

[jcjgraf]

I have tested the reported cases and your PR seems to fix them. I was also not able to observe anything unusual when using tiles in the file name.

[TeaWhyDee]

I have tested it, the ~ is still broken. Reproducible example command:

xt : !notify-send "%%"

Running this on "IMG.jpg~":

The issue seems to persist with other special symbols too in case of external commands.

[karlch]

Thanks, I can reproduce it with external commands, especially together with quoting this is complete havoc currently.

I believe we will have to clarify and change some of the requirements here.

In principle we have a matrix of combinations here, with different wildcards as the rows (internal like %, the tilde, python globbing, shell expansion) and different command types as the columns (regular command, path command such as :open, external without sub-shell using !, external with sub-shell using :spawn). Summarized here quick and dirty:

yes / no indicates whether this combination should be supported. I am unsure on the ones colored, any feedback or discussion would be great. Here green means this is the way it is currently, red is a deviation.

Removing globbing from external commands would save us a lot of escaping-havoc, and we could strictly split shell escaping and glob escaping, as they never overlap. I am honestly not 100 % sold on changing this, yes it could be useful to run something along !rm **/*.png, but really this should probably be done without vimiv then. And one could still do :mark **/*.png followed by !rm %m.

tl;dr different wildcards meet different command types, can we remove globbing from external commands? Should we add some further expansions to internal (non-path) commands?

[TeaWhyDee]

I think globbing could be useful in external commands. I don't think it's currently possible to escape the globbing symbols? I think either it should be removed or \ escaping added.
Something like :mark IMG*.jpg and :mark IMG\*.jpg still marks all glob matching images (and this auto-completes).

As for the external commands issue, tilde and globbing expansion could probably be done before internal symbol expansion so the issue doesn't occur?

[karlch]

Works with two backslashes, i.e. :mark IMG\\*.jpg, don't ask why 😆
Now I agree it should escape in the completion, and one backslash should be enough of course.

I am not really sold on globbing in external commands though. Mainly to avoid actually using a sub-shell with :spawn? Or for the additional ** feature which not all shells have?