cape-company-to-capf: Overhaul candidate lookup in :exit-function

The :exit-function looks up the candidate in order to restore text properties.
This lookup is not necessary with Corfu, which guarantees that the candidates
are propertized. The lookup even hurts since duplicate candidates lose their
specificity, they would get replaced by their first occurrence in the candidate
list.

1 files changed, 17 insertions, 10 deletions

diff --git a/cape.el b/cape.el
index 4c9ec3c..531e4a8 100644
--- a/cape.el
+++ b/cape.el
@@ -786,7 +786,7 @@ changed.  The function `cape-company-to-capf' is experimental."
       (let* ((end (point)) (beg (- end (length initial-input)))
              (valid (if (cape--company-call backend 'no-cache initial-input)
                         #'equal (or valid #'string-prefix-p)))
-             candidates)
+             restore-props)
         (list beg end
               (funcall
                (if (cape--company-call backend 'ignore-case)
@@ -796,8 +796,15 @@ changed.  The function `cape-company-to-capf' is experimental."
                 (cape--dynamic-table
                  beg end
                  (lambda (input)
-                   (setq candidates (cape--company-call backend 'candidates input))
-                   (cons (apply-partially valid input) candidates)))
+                   (let ((cands (cape--company-call backend 'candidates input)))
+                     ;; The candidate string including text properties should be
+                     ;; restored in the :exit-function, if the UI does not
+                     ;; guarantee this itself.  Restoration is not necessary for
+                     ;; Corfu since the introduction of `corfu--exit-function'.
+                     (unless (and (eq completion-in-region-function 'corfu--in-region)
+                                  (fboundp 'corfu--exit-function))
+                       (setq restore-props cands))
+                     (cons (apply-partially valid input) cands))))
                 :category backend
                 :sort (not (cape--company-call backend 'sorted))))
               :exclusive 'no
@@ -809,13 +816,13 @@ changed.  The function `cape-company-to-capf' is experimental."
               :company-kind (lambda (x) (cape--company-call backend 'kind x))
               :annotation-function (lambda (x)
                                      (when-let (ann (cape--company-call backend 'annotation x))
-                                       (if (string-match-p "^[ \t]" ann)
-                                           ann
-                                         (concat " " ann))))
-              :exit-function
-              (lambda (x _status)
-                (cape--company-call backend 'post-completion
-                                    (or (car (member x candidates)) x))))))))
+                                       (concat " " (string-trim ann))))
+              :exit-function (lambda (x _status)
+                               ;; Restore the candidate string including
+                               ;; properties if restore-props is non-nil.  See
+                               ;; the comment above.
+                               (setq x (or (car (member x restore-props)) x))
+                               (cape--company-call backend 'post-completion x)))))))
 
 ;;;###autoload
 (defun cape-interactive (&rest capfs)