`editor-command` doesn't work everywhere, quotes seem to break it, and `;e` doesn't offer hints

[John Z.]

Steps to reproduce

1. set editor-command according to doc in config file: (#set editor-command=termite -e "nvim %s")
   set editor-command=urxvt -e vis %s (note lack of quotes!)
2. try executing it on archlinux forums using ;e and CTRL-T. Also attempt Amazon and DuckDuckGo

Expected behaviour

Urxvt window with vis instance opens up, with text from the hinted field. When closed, contents would be transferred over to the hinted field.

Actual behaviour

1. If quotes are retained, as in example - there is a quick flash then nothing happens. I presume Urxvt opens then immediately closes as quotes seem to break the command somehow
2. on all three sites, hints aren't shown, but first field is sent to the external editor. This is understandable for archlinux forums and duckduckgo (as there's only one field), but amazon's Order page has two (search and search orders)
3. on archlinux forums contents aren't transferred back into the post field. On duckduckgo, sometimes the searchbar contents are transferred to editor as 'undefined', and not transferred back (works second time around though). On amazon everything works, except I can't hint the field I'd like. If I manually hint at the field using f first, then it works normally.

Vimb --bug-info

Version:         3.6.0-58-gabff254
WebKit compile:  2.34.5
WebKit run:      2.36.3
GTK compile:     3.24.31
GTK run:         3.24.34
libsoup compile: 2.74.2
libsoup run:     2.74.2
Extension dir:   /usr/lib/vimb

Not using wyebadblock, but using hblock. No idea if that matters, but worth pointing out.