Latest version breaks org-refile: "sort: Wrong type argument: stringp"

[kirill-gerasimenko]

Hi,

The latest version (3689c8f) breaks 'org-refile' for me.

The error looks like this:
sort: Wrong type argument: stringp, ("Когда едешь назад раздается звук, как хрустит/" "e:/service.org" "^\\(\\*+\\)\\(?: +\\(DONE\\|TODO\\)\\)?\\(?: +\\(\\[#.\\]\\)\\)?\\(?: +\\(?:\\[[0-9%/]+\\] *\\)*\\(Когда едешь назад раздается звук, как хрустит\\)\\(?: *\\[[0-9%/]+\\]\\)*\\)\\(?:[ ]+\\(:[[:alnum:]_@#%:]+:\\)\\)?[ ]*$" 188)

Reverting back to https://github.com/abo-abo/swiper/blob/4fef67fd0bab6c98ed9ad36a4c795515e24e52de/ivy.el makes it work again.

My system is Windows 10, GNU Emacs 26.1 (build 1, x86_64-w64-mingw32) of 2018-04-06

I can provide more info if needed.
Thanks!

[basil-conto]

I think this is because org-refile's collection is an alist, so trying to sort it in ivy--reset-state with the default fallback string-lessp from ivy-sort-functions-alist fails.

While glancing at ivy--reset-state, I also noticed a less serious potential issue with sorting: caller and this-command aren't consistently considered synonyms.

[basil-conto]

There is an ambiguity in the ivy-sort-functions-alist API: does the sorting function apply to string candidates regardless of the type of collection, or does it apply directly to the collection as it was originally specified? For example, when the collection is an alist, does the sorting function apply to cells, or to their CARs? FWIW, I think the former is more flexible, but the latter is by far the more user-friendly.

Yet another potential issue is that ivy-sort-functions-alist states that each of its CDRs can be a list of functions, whereas current usage of ivy--sort-function assumes they comprise a single function.

[basil-conto]

Oh, just noticed this issue is a duplicate of #1565.

[basil-conto]

For example, when the collection is an alist, does the sorting function apply to cells, or to their CARs? FWIW, I think the former is more flexible, but the latter is by far the more user-friendly.

Ah, but #554 says the sorting function should apply to the collection as it was provided. This rules out string-lessp as a suitable fallback in ivy-sort-functions-alist, right?

[abo-abo]

This seems be fixed in #1568. Please verify.

[kirill-gerasimenko]

Thanks, it works now!