### Please describe the problem.

When using the metadata driven view fields values that contain a slash break the view field=* functionality

### What steps will reproduce the problem?

    $ git annex metadata --set test=a/b file.tex
    $ git annex view test=*    
    view  (searching...) 
    git-annex: fd:13: commitBuffer: invalid argument (invalid character)
    failed
    git-annex: view: 1 failed

    

### What version of git-annex are you using? On what operating system?

git-annex version: 5.20151218-g5008846 on ArchLinux


### Please provide any additional information below.

To me it seems like this is only occuring during a field=* view.
Everywhere else the field value behaves normally, For example its possible to directly address the field value in a view without issue.

    $ git annex view test=a/b
    view  (searching...) 
    Switched to branch 'views/(test=a/b)'
    ok


I dont have any issues with non latin characters so this doesnt seem related to the locale issues in [https://git-annex.branchable.com/bugs/view_fails_with___34__invalid_character__34__/](https://git-annex.branchable.com/bugs/view_fails_with___34__invalid_character__34__/)

I was trying out the metadata extraction via libextractor and for the mimetype there often are slashes involved.


### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

Apart from this git-annex is working very well for me. I mostly use it as an archive, distributing numerous copies on various hard drives and cloud providers and keeping track of what is where.Its an amazing tool for that.


> [[done]] --[[Joey]] 
