swiper-all navigation breaks after invalid regexp

[Wilfred]

Given a buffer with the following contents:

foo=[1,2,3]
foo=[4,5,6]

And the following ivy settings:

(setq ivy-re-builders-alist '((t . ivy--regex-ignore-order)))

M-x swiper-all RET foo=\[ breaks ivy. I cannot move between results in the minibuffer (e.g. by pressing C-n and C-p).

I get the following error in *Messages*:

Error in post-command-hook (ivy--exhibit): (invalid-regexp "Trailing backslash")

The problem seems to occur when I've typed foo=\ but haven't yet typed the [.

[abo-abo]

Thanks for the report, I can reproduce it.

I never use ivy--regex-ignore-order and don't have too much time right now, so I would really appreciate a PR with a fix.

Here's what a volunteer can do:

1. Eval this to see the error comes from a bad regex:

   (swiper-all-function "foo=")

2. Eval this to see where the bad regex comes from:

   (ivy--regex-ignore-order "foo=")
   ;; =>
   ;; (("foo=" . t))

3. Update ivy--regex-ignore-order to return "foo=\\\\" in this case.

4. Add an ERT test for this to ivy-test.el.

[Wilfred]

Thanks, that's really helpful. I've created a PR along the lines you described.